Jimmy Carter, who rose from Georgia farmland to become the 39th president of the United States on a promise of national healing after the wounds of Watergate and Vietnam, then lost the White House in a cauldron of economic turmoil at home and crisis in Iran, died on Sunday at his home in Plains, Ga. He was 100.

The Carter Center in Atlanta announced his death, which came nearly three months after Mr. Carter, already the longest-living president in American history, became the first former commander in chief to reach the century mark. Mr. Carter went into hospice care 22 months ago, but held on longer than even his family expected.

Tributes poured in from presidents, world leaders and many everyday people from around the world who admired not only Mr. Carter’s service during four years in the White House but his four decades of efforts since leaving office to fight disease, broker peace and provide for the poor. President Biden ordered a state funeral to be held and was expected to deliver a eulogy.

“To all of the young people in this nation and for anyone in search of what it means to live a life of purpose and meaning — the good life — study Jimmy Carter, a man of principle, faith and humility,” Mr. Biden, the first Democratic senator to endorse Mr. Carter’s long-shot 1976 bid for the presidency, said in a statement. “He showed that we are great nation because we are a good people.”

President-elect Donald J. Trump, who often denigrated Mr. Carter and in recent days spoke of unraveling one of his signature accomplishments, the transfer of the Panama Canal to Panama, issued a gracious statement. “The challenges Jimmy faced as president came at a pivotal time for our country, and he did everything in his power to improve the lives of all Americans,” Mr. Trump said. “For that, we owe him a debt of gratitude.”

Mr. Carter was no fan of Mr. Trump and family members said he was holding on in part to vote for Vice President Kamala Harris. The former president cast his absentee ballot for her in mid-October after making his final public appearance on his birthday when he was rolled out to his yard in a wheelchair to watch a flyover of military jets in his honor.

Other than interludes in the White House and the Georgia governor’s mansion, he and his wife, the former first lady Rosalynn Carter, lived in the same simple home in Plains for most of their adult lives and each of them passed away there, Mrs. Carter in November last year.

A lifelong farmer who still worked with his hands building houses for the poor well into his 90s, Mr. Carter had long defied death and outlived not only his wife but his vice president, most of his cabinet, key aides and allies as well as the Republican president he defeated and the Republican challenger who later defeated him. Over the years, he beat back a series of health crises, including a bout with the skin cancer melanoma, which spread to his liver and brain, and repeated falls, one giving him a broken hip.

The Carter Center announced in February last year that Mr. Carter, “after a series of short hospital stays,” had decided to forgo further life-prolonging medical treatment and would receive hospice care at home.

News that he seemed to be in his final days prompted a wave of tributes and remembrances of his extended and eventful life, but even then he upended expectations by hanging on for nearly two years. He lived long enough to bid farewell to Mrs. Carter, who died at 96, culminating a marriage of 77 years.

Mr. Carter’s death sets the stage for the first presidential funeral since that of George H.W. Bush in 2018, to culminate in a service at Washington National Cathedral. Such occasions traditionally prompt a cease-fire in America’s fractious political wars as the nation’s leaders pause to remember and bid farewell to one of their own. It was not immediately clear whether Mr. Trump would attend.

With his peanut farmer’s blue jeans, his broad, toothy grin and his promise never to tell a lie, Mr. Carter was a self-professed outsider intent on reforming a broken Washington in an era of lost faith in government. He became one of his generation’s great peacemakers with his Camp David accords, bringing together Israel and Egypt, but he could not turn around a slumping economy or free American hostages seized by militants in Iran in time to win a second term.

While his presidency was remembered more for its failures than for its successes, his post-presidency was seen by many as a model for future chief executives. Rather than vanish from view or focus on moneymaking, he established the Carter Center to promote peace, fight disease and combat social inequality. He transformed himself into a freelance diplomat traveling the globe, sometimes irritating his successors but earning the Nobel Peace Prize in 2002.

Mr. Carter was outspoken into his final years. He condemned the attack on the Capitol on Jan. 6, 2021, by a mob of Mr. Trump’s supporters trying to overturn his election defeat to Mr. Biden, and he denounced new voting limits subsequently passed by Republicans in Georgia. In an essay for The New York Times on the first anniversary of Jan. 6, he warned that “our great nation now teeters on the brink of a widening abyss” and called for changes to avoid “losing our precious democracy.”

Long a favorite target for Republicans, Mr. Carter’s name came up repeatedly as a foil for Mr. Trump to mock Mr. Biden even after the incumbent president withdrew from this year’s race. “Jimmy Carter is the happiest man because Jimmy Carter is considered a brilliant president by comparison,” Mr. Trump said on Mr. Carter’s 100th birthday. Mr. Biden’s critics compared high inflation on his watch to the price increases of Mr. Carter’s presidency, and the fall of Afghanistan to the Iran hostage crisis.

Mr. Carter went to Washington with an outsider’s promise to “drain the swamp” and make America great again four decades before Mr. Trump expressed those same aims. But the two could hardly have come from more different origins. Unlike the thrice-married New York playboy mogul with the flashy golf resorts and the private airliner, Mr. Carter grew up on a peanut farm with no electricity or running water. He was a frugal born-again Christian who taught Sunday school and was married to the same woman for more than three-quarters of a century.

He was a man of the people, or so he wanted to be perceived. Minutes after his Inaugural Address in January 1977, he surprised the crowds lining Pennsylvania Avenue when he and Rosalynn Carter and their 9-year-old daughter, Amy, got out of the presidential limousine and walked the parade route to the White House, smiling and waving in the sunshine as spectators cheered.

Mr. Carter once said that he had gone to the capital to restore the country’s faith in itself after the twin traumas of Watergate and Vietnam — to build a “new foundation,” as he put it, of trust, decency and compassion.

Meeting that goal would have been hard enough without the intrusions of national and international crises. His four-year tenure was a story of distraction, disappointment and serial drama that came to an end only in the last tortured minutes of his presidency, with the release of Americans held hostage by Iranians for 444 days.

Troubles and Triumphs

To his critics, Mr. Carter often undermined his own ambitions through stubbornness and insufficient attention to the egos and political needs of others in the government. His unorthodox style — informal in his cardigan sweaters but uncomfortable with the glad-handing ways of Washington — and an unfortunate confluence of circumstances cost him dearly in the domestic arena.

There was an intractable energy problem brought on by an Arab oil embargo. Inflation soared, and so did interest rates, leaving businesses and home buyers deeply discouraged. He found himself at odds with an increasingly assertive Congress controlled by his own party. His approval rating in the polls sank from 70 percent early in his presidency to 28 percent little more than a year later.

He nevertheless achieved some notable successes in office, particularly in foreign affairs. His human rights policies set a new standard for how the United States should deal with abusive governments. He hammered out a peace treaty between Israel and Egypt that still holds decades later. He signed a strategic arms limitation agreement with the Soviet Union. He formalized diplomatic relations with China. And over the opposition of conservatives like Ronald Reagan, he pushed through treaties turning over the Panama Canal to Panama.

Long pilloried by Republicans as a model of ineffectual liberal leadership and shunned by fellow Democrats who saw him as a political albatross, Mr. Carter benefited in recent years from some historical reappraisal, reinforced by Mr. Biden’s visit in 2021 and a gala celebration of the Carters’ 75th wedding anniversary three months later. Several recently published books argued that his presidency had been more consequential than it was given credit for.

In “His Very Best: Jimmy Carter, a Life,” published in 2020, Jonathan Alter called him “perhaps the most misunderstood president in American history,” one who was ahead of his time on the environment, foreign policy and race relations.

Similarly, Kai Bird maintained in “The Outlier: The Unfinished Presidency of Jimmy Carter” (2021) that the traditional view of Mr. Carter as a better former president than president was belied by the historical evidence. “The record of these achievements is not to be lightly dismissed,” he wrote.

And Stuart E. Eizenstat, Mr. Carter’s domestic policy adviser, insisted in “President Carter: The White House Years” (2018) that the former president was a thoroughly decent, honorable man who had been underrated. While he may have been miscast as a politician, Mr. Eizenstat wrote, Mr. Carter’s accomplishments, measured against those of other presidents, made him “one of the most consequential in modern history.”

A son of a small-town businessman and farmer, Mr. Carter was the first president from the states of the former Confederacy to be elected since the Civil War, not counting Woodrow Wilson, a Virginian who had moved to New Jersey, where he taught and served as governor, and Lyndon B. Johnson, a Texan who ascended to the Oval Office upon the assassination of his predecessor before being elected to a full term. To many Americans it was remarkable that a molasses-voiced Southerner from what had been a white-supremacist section of Georgia could win the presidency just over a decade after the death of Jim Crow.

Defeated in 1980 by Mr. Reagan, Mr. Carter went home to Plains not only disappointed but also worn in body and spirit. Then he set about rebuilding. He became a global humanitarian, an author, a professor and a wealthy landowner, engaging in public affairs to a degree not seen among former presidents in modern times.

While he had first made his mark in national politics as a relatively moderate Democrat — he started the military buildup that Mr. Reagan would later expand while presiding over smaller deficits than his successor did — Mr. Carter migrated to the left in the years after office. By 2016, he supported Senator Bernie Sanders, the democratic socialist from Vermont, over former Secretary of State Hillary Clinton, the more centrist party favorite, for the Democratic presidential nomination.

In his path to power, Mr. Carter had pledged a government “as good as the American people,” but he showed little talent for the compromise and dealing that politics demands. He envisioned fundamental changes in policies ranging from taxes to the organization of federal agencies, but he found that Congress was unwilling or unable to enact them. He had been trained as an engineer and a problem solver, but he came up against a nation that had grown hesitant, drained and divided by war in Southeast Asia and demoralized by scandal in the White House.

When Mr. Carter announced his presidential candidacy in 1974, his political qualifications seemed unexceptional. He had been governor of Georgia for a single term and before that a state senator. He started adulthood as a Navy officer, then went home to run the family business. His first dalliance with politics was little more than the expression of civic involvement expected of such men in small towns everywhere.

Then, as his interest in public affairs deepened, it became obvious that the man was not ordinary and never had been. There was an intensity about him, a drive to learn and excel, that few outside his family and friends had noticed.

He was similarly underestimated when he walked onto the national stage in the 1970s. And even after voters had elected him president in 1976, they still knew little about him, except that they liked him and that he seemed to be honest and decent and untainted by the nation’s recent dishonor.

Peanuts, Bibles and Politics

James Earl Carter Jr. was born in Plains on Oct. 1, 1924, into a family not wealthy but “well off,” as Southerners put it. His father, who was known as Earl, owned enough fertile land to make a comfortable living growing peanuts, cotton and other crops. Jimmy’s mother, Lillian (Gordy) Carter, was a nurse and an avid reader with a keen interest in public affairs.

Their son would become known for his strong Baptist faith, but Earl and Lillian wore their religion more lightly. They and their friends raised eyebrows in their Bible Belt town by partying on Saturday nights with liquor and dancing. Come Sunday morning, however, they all showed up at church.

Jimmy inherited a taste for politics from both sides of his family. His maternal grandfather, James Jackson Gordy, was a friend and follower of the Georgia populist Tom Watson, a confounding mixture of race-baiter and civil liberties champion. Earl Carter was a disciple of Eugene Talmadge, the segregationist governor of Georgia.

Jimmy Carter’s attitude toward race was shaped by a Southern complexity in which white people would keep their distance from Black people in town, expressing contempt for them there if not outright hostility, and then work side by side with them on the farm, where Black and white children might play together.

Mr. Carter spent a lot of time with his Black neighbors. “I played with their children, often ate and slept in their homes, and later hunted, fished, plowed and hoed with their husbands and children,” he wrote in a 2001 memoir, “An Hour Before Daylight: Memories of a Rural Boyhood.”

His father’s racial attitudes were typical of the time and place. Earl Sr. treated Black neighbors fairly, the younger Mr. Carter said, but insisted on the customary boundaries. His mother, on the other hand, refused to acknowledge most racial distinctions. Years later, when Lyndon Johnson ran for president, Miss Lillian, as she was known, managed his local campaign office. Segregationists repeatedly vandalized her car.

The Carter farm was at Archery, a hamlet just west of Plains that no longer exists. Jimmy lived there — in a one-story white-frame house, now a National Historic Site — from 1928 through the Depression. He saw many sharecropper families subsisting on fatback, cornmeal and molasses with an occasional squirrel or possum.

Jimmy learned the proper way to cook possum. “They were always baked whole,” he wrote, “smothered in sweet potatoes, apples, or other fruits, vegetables and spices that never adequately concealed their unique taste.”

By 1937, three other children had been born into the Carter house: Gloria in 1926, Ruth in 1929 and Billy in 1937.

Their living was primitive by today’s standards. They drew water from a well and relieved themselves in an outdoor privy. One of Jimmy’s first chores was milking the cows.

Jimmy exerted himself to learn all he could about running a farm. Even so, he harbored an ambition to go to sea one day. He set his sights on Annapolis and a career as a naval officer.

He was 16 when he graduated from Plains High School at the top of his class of 26 — the first in his family to finish high school. He went on to spend a year at Georgia Southwestern College in nearby Americus and a year at Georgia Tech in Atlanta. Then, in 1943, with the United States far into World War II, he was accepted into the Naval Academy at 19. He spent the rest of the war there in an accelerated program and graduated in 1946.

A month later he married Rosalynn Smith, a friend of his sister Ruth’s. Rosalynn had briefly attended Georgia Southwestern and was ready to leave Georgia.

The Navy gave the Carters a look at the world. Their first son, John, known as Jack, was born in Portsmouth, Va., in 1947; James Earl Carter III, known as Chip, was born in Honolulu in 1950; and the third son, Donnel, was born in New London, Conn., in 1952. (Their daughter, Amy, came along much later in Plains, in 1967.)

In October 1952, Lieutenant Carter went to work for Capt. Hyman Rickover, who was well along in developing the Navy’s first nuclear-powered submarines and ships. After going back to school to study nuclear engineering, Lieutenant Carter became the executive officer in a crew that would build and prepare the first nuclear submarine, the Nautilus. By the winter of 1953, he was dreaming of commanding his own sub.

Then, on July 23, 1953, his father, at that point a member of the Georgia House of Representatives, died of pancreatic cancer, the disease that would take the lives of three of his children, though not his son Jimmy’s.

Lieutenant Carter resigned his commission, angering Rickover, and returned to Plains to take over the family’s peanut warehouse and processing plant, angering Rosalynn; she had no interest in going back to Georgia.

No to Segregationists

These were lean times; the business earned less than $200 in net profit the first year. But with Rosalynn keeping the books and both working long hours, they built it into a profitable operation.

Mr. Carter became a civic leader, spearheading the building of the town’s first swimming pool, leading an effort to pave its streets, helping to bring a doctor to town and getting appointed to the Sumter County school board.

But tensions rose as the civil rights movement gained steam, and when a White Citizens Council was formed to resist integration in Plains, Mr. Carter refused to join. His business was briefly boycotted, but he rode out the trouble and mostly avoided speaking publicly about race. Still, word got around that he and Rosalynn were different from most white Georgians.

Deciding to go into politics, he ran for the State Senate in 1962 and won. Months later, civil rights activists moved into Americus, in his district. The police used violence to break up demonstrations, and obscure laws were used to jail protesters. But as the national media covered the turmoil, Mr. Carter kept silent rather than join the cry of resistance that most white Southerners expected of their political leaders at the time.

As a state senator, Mr. Carter soon proved politically nimble, befriending progressives in the capital while treading the fine line between segregationists and integrationists in his rural district. His constituents tolerated him even when he spoke out in favor of admitting Black people to Plains Baptist Church, where the vote was 54 to 6 against it.

Increasingly confident of his political skills, Mr. Carter ran for governor in 1966. But he came in third in a six-man race, drawing enough votes to contribute to the failure of a fellow progressive, former Gov. Ellis Arnall, who was forced into a runoff against the arch-segregationist Lester Maddox. Maddox won, a victory for which a dismayed Mr. Carter held himself partly responsible.

Mr. Carter immediately planned to run again in 1970. Guided by his sister Ruth, a charismatic religious leader, he became newly serious about his faith, describing himself as a born-again Christian. His mother, in her late 60s, was undergoing a conversion of sorts at the same time. In 1966, bored and restless, she joined the Peace Corps. She learned two languages and spent the next years teaching nutrition in India.

For his run for governor in 1970, Mr. Carter gathered a staff of up-and-coming Georgians, Black and white, including Mr. Eizenstat, Hamilton Jordan, Jody Powell, Bert Lance, Vernon Jordan and the Rev. Andrew Young, all of whom remained close to him as president.

With a deft though vague message that appealed to both liberals and conservatives, Mr. Carter handily defeated Carl Sanders, a former governor with a progressive image. While he had appealed during the campaign to supporters of George C. Wallace, the segregationist governor of Alabama, Mr. Carter stunned his conservative backers when he stood in front of the Capitol and proclaimed in his inaugural address, “I say to you quite frankly the time for racial discrimination is over.”

Before summer, Mr. Carter was on the cover of Time magazine, hailed as one in a wave of “New South” governors elected in 1970.

‘President of What?’

Jimmy Carter’s quest for the White House began in the fall of 1972 as it became clear that Senator George S. McGovern, the Democratic nominee, would lose to President Richard M. Nixon in November. Mr. Carter and his advisers calculated that the Democratic field in 1976 would be wide open and that a newcomer would have a chance.

He was encouraged by Peter Bourne, a British psychiatrist who had landed in Georgia and joined Mr. Carter’s staff to work on health matters. Dr. Bourne had written a 10-page memorandum to Mr. Carter during the 1972 Democratic National Convention, when Mr. Carter had hopes of being Mr. McGovern’s running mate. Dr. Bourne urged him to aim higher than vice president and to start campaigning for the presidency early. Mr. Jordan wrote a similar memo.

Dr. Bourne’s optimism was based on the presumption that a Carter campaign would signal a departure from the old politics of race. “No Southerner has captured the presidency,” Dr. Bourne wrote, “because he has not been willing to take the drastic step away from traditional Southern politics that is necessary.” (Lyndon Johnson, who came from Texas, succeeded to the office after the assassination of John F. Kennedy and was a sitting president when elected outright.)

Mr. Carter was willing and able to take that step because of a new Southern political reality that had been fostered by the civil rights movement and Johnson’s leadership in dismantling the legal underpinnings of Jim Crow, including the disenfranchisement of Black voters. No longer necessarily tethered to that segregationist legacy, white Southerners could henceforth run for national office on an equal footing with others, although for years they would have to demonstrate that they were not racists.

The day after Mr. McGovern’s resounding defeat, Mr. Carter summoned several advisers to the Georgia governor’s mansion to begin planning his presidential run. The group assumed that his main rivals for the Democratic nomination in 1976 would be Wallace and Senator Edward M. Kennedy of Massachusetts. Wallace was recovering from wounds at the hands of a would-be assassin earlier that year. By Christmas 1972, the Carter campaign was quietly underway.

Two months later, Mr. Carter spoke to the National Press Club in Washington, laying out a vision for the nation that combined populism, frugality and criticism of Nixon, the latter a note that would sound prescient during the unfolding Watergate scandal just ahead.

Mr. Carter recognized that he was weak on foreign affairs at the time. So in April 1973, he and Rosalynn Carter brushed up on their Spanish and led a delegation of Georgians on a trade mission to Latin America. A month later, he and his group were in Britain, West Germany, Belgium and Israel. He accepted an appointment to the Trilateral Commission, which had been created by the banker David Rockefeller in 1973 as a forum for political and business figures from North America, Western Europe and Japan. The director was the political scientist Zbigniew Brzezinski.

Mr. Carter extended his reach in the national party in 1974 as chairman of the midterm elections campaign. Democrats were emboldened in the wake of Watergate, and he traveled the country to speak for 62 candidates for Congress. In the November election, Democrats made large gains in the House and the Senate as well as in statehouses across the nation. Within weeks Mr. Carter announced his intention to run for president.

Many observers were incredulous and shared the reaction of his plain-spoken mother, Lillian: “President of what?”

His brother, Billy, who had acquired the image of a beer-guzzling Southern good old boy, had misgivings of his own. When a reporter suggested to him that he was a little strange, he replied: “Look, my mama was a 70-year-old Peace Corps volunteer in India, one of my sisters goes all over the world as a holy-roller preacher, my oldest sister spends half her time on a Harley-Davidson motorcycle, and my brother thinks he’s going to be president of the United States. Which one of my family do you think is strange?”

But the dark horse’s chances improved as Senator Kennedy made no moves toward a candidacy and Wallace’s health failed to improve. The early campaign, short on funds, gave new meaning to the term grass roots. Mr. Carter flew coach and saved on lodging by staying with families, some poor, as he crisscrossed the nation. He generated support among establishment figures like Cyrus R. Vance, Warren M. Christopher and Richard C. Holbrooke and made inroads in organized labor, the entertainment industry and the news media.

For the first time since 1960, when John F. Kennedy had to assert that his Roman Catholicism would not influence his White House decision making, religion became an issue in a presidential campaign. By labeling himself a born-again Christian, Mr. Carter appealed to many voters, especially Black fellow Baptists. But to others his religiosity seemed self-righteous and vaguely alarming.

The religion issue subsided, then erupted again when he acknowledged to Playboy magazine that he had lusted in his heart for women besides his wife. He was trying to explain Jesus Christ’s admonition that people should not harshly judge one another; he himself, Mr. Carter said, should not look down on the man who has committed adultery. Nuance was lost, however, and he endured weeks of anger, ridicule and jokes.

Mr. Carter’s strategy for 1976 was to win the early nomination contests and build momentum. It worked. He practically planted himself in Iowa — where few presidential hopefuls had ever taken its complicated January caucuses all that seriously before — and stunned the political world by surpassing every other candidate. (The victory put Iowa on the presidential map in future races, a status diminished when Mr. Biden ended its first-in-the-nation position for Democrats earlier this year.) Mr. Carter parlayed his success into a victory in the New Hampshire primary in February.

By the end of the primary season, he had outpaced a field that included not just Wallace but prominent Democrats like R. Sargent Shriver, the Kennedy family member and former vice-presidential nominee, and Gov. Jerry Brown of California.

The party formally nominated Mr. Carter on July 15 at Madison Square Garden in New York, and he selected Senator Walter F. Mondale of Minnesota as his running mate, balancing out his ticket with a liberal Washington insider who had strong labor ties.

In the general election, Mr. Carter took on President Gerald R. Ford, who had succeeded to the office with Nixon’s resignation in 1974 and then controversially pardoned him. Mr. Carter argued that after Watergate it was time for a change in Washington. “I will never lie to you,” he promised.

His campaign was aided by the poor economy. He cited the “misery index,” the combination of inflation and unemployment rates, which reached 13 percent by Election Day. On Nov. 2, 1976, Mr. Carter defeated Ford with 297 electoral votes to 240, and 50.1 percent of the popular vote to 48 percent for the incumbent.

President Everyman

On Jan. 20, 1977, Mr. Carter opened his Inaugural Address by thanking Ford “for all he has done to heal our land.” It sounded a therapeutic tone that he would seek to sustain.

He made a point of deconstructing the imperial presidency associated with Nixon, presenting himself as an Everyman. In addition to walking the route of his inaugural parade, he banned the playing of “Hail to the Chief,” sold the presidential yacht Sequoia and carried his own bags onto Air Force One.

Mr. Carter’s first act as president was to grant amnesty to Vietnam War draft resisters. The predicted firestorm raged then quickly faded. He had fulfilled his first campaign promise, part of his plan to bind up the nation’s wounds. Warned that the order would be fiercely opposed in the Senate, as indeed it was, he replied: “I don’t care if all 100 of them are against me. It’s the right thing to do.”

Mr. Carter immediately tried to allay any lingering doubts about his stand on race. One of his first appointments, ambassador to the United Nations, was Mr. Young, his Atlanta friend and a former aide to the Rev. Dr. Martin Luther King Jr. It was the first of many minority appointments.

He was also attentive to placing women in high positions. One was Patricia Derian of Jackson, Miss., a white civil rights leader, who turned the position of assistant secretary of state for human rights into an instrument of pressure on abusive strongmen around the world.

Ms. Derian’s husband, Hodding Carter III, another Mississippian, became even more prominent as the State Department’s chief spokesman. During the Iran hostage crisis, the face of Hodding Carter (no relation to Jimmy Carter) became almost as familiar on television as the president’s.

The president himself was on television almost daily in his first months in office. He held news conferences twice a month and addressed “town meetings” around the country. In his televised “fireside chats” — reminiscent of Franklin D. Roosevelt’s radio addresses from the White House — he spoke to the citizenry wearing a fatherly cardigan sweater rather than a suit. He answered questions on a national radio broadcast.

Surrounded by the “Georgia Mafia” he had taken with him to the White House, Mr. Carter refused at first to have a chief of staff, preferring what was called a “spokes of the wheel” structure in which many advisers had access to him. As it turned out, he was a micromanager, drawing scorn for keeping tabs even on the schedule of the White House tennis court.

Part of his problem could be traced to a cultural gap between Mr. Carter’s team and the Washington sophisticates who set the tone in national affairs. The Southerners, wearing bluejeans to work and acting boisterous in public after hours, were greeted skeptically in some quarters and often ridiculed.

The Washington Star saluted the new administration with a page of mocking cartoons by Patrick Oliphant. In one, Lillian Carter wore a sunbonnet and smoked a corncob pipe; an outhouse could be seen on the White House lawn.

There was similar comment overseas. In London, the humor magazine Punch published a weekly column titled “Miz Lillian Writes,” composed in an exaggerated Southern patois. The president’s mother was portrayed as a crude racist, though she was perhaps the oldest white integrationist in Plains.

The administration had its first hint of scandal in September 1977, when Mr. Lance, the director of the Office of Management and Budget and a close Carter friend, was forced to resign after allegations of civil fraud and numerous violations of banking and securities laws during his Atlanta days. A federal jury later acquitted him and his associates on nine counts of banking law violations but deadlocked on three other counts.

In response to criticism that his presidency was all style and no substance, Mr. Carter proposed tax reform, an overhaul of the welfare system and a comprehensive approach to the energy problem. He offered policies to halt the decline of cities, tackled inflation and unemployment, and sought increased spending for guns and butter while preaching the necessity of a balanced budget.

His foreign affairs list was just as long: disarmament; a new international respect for human rights; meaningful dialogue with developing nations; closer ties with Latin America; resolution of the Middle East conflict; better relations with the Soviet Union; and, presaging his first big fight with Congress, a pair of treaties turning over the Panama Canal to Panama.

The upshot was that he overloaded Congress with proposals. “The president personally tries to solve too many problems,” Attorney General Griffin B. Bell said when he resigned in 1979 to return to private law practice. “The president can’t spend his time on minutiae. He’s got to deal with the big things, like inflation.”

‘Sacrifice and Pain’

Despite his infectious smile, Mr. Carter was an introvert at heart and faced policy challenges like an engineer, not a politician. He could be priggish and even moralistic. He made little allowance for the political needs of his own allies, alienating fellow Democrats in Congress, especially the House speaker, Thomas P. O’Neill of Massachusetts. Mr. Carter “did not like politicians and felt uncomfortable with the normal byplay of political compromise,” Mr. Eizenstat wrote in his 2018 book.

As a result, Mr. Carter’s legislative record was mixed. He created a Department of Energy and a Department of Education, both of which would go on to survive generations of Republicans who vowed to eliminate them. But other proposals, like a wellhead tax on new oil, went down to defeat.

Circumstances outside his control made matters worse. The Iranian revolution in late 1978 cut oil production in Iran and increased energy problems in the United States. There were long lines at gasoline stations. To alleviate the pain, Mr. Carter, by executive action, ended controls on the price of domestically produced oil.

Stung by criticism that he did not appreciate the ways of Washington, the president changed his style during the spring of 1978. He reined in freewheeling cabinet officers and put more power in the White House. He gave senior White House staff members more authority, overcoming his initial fear of creating another Nixon White House. He reluctantly decided to grasp the levers of power and play the political game.

By the end of his second year, Mr. Carter had succeeded in pushing through a Democratic-controlled Congress a tax cut, Civil Service reorganization and an energy bill that had been significantly changed from his original proposal. He vetoed bills for public works and the military that he deemed “inflationary.”

But Congress refused to act on other initiatives, including parts of his urban aid programs and his plan to scrap welfare programs in favor of a system of cash grants for those who were not expected to work.

He tried to balance the budget. He also wanted to increase military spending, so he proposed cutting social programs, but that provoked warnings of social unrest from members of Congress and leaders of Black organizations. The criticism was only partly blunted by his appointment of more Black and Hispanic people than any president before him.

Mr. Carter took strong environmental stands, but problems persisted in hazardous wastes, water resources, wildlife protection and coastal conservation. After a partial meltdown of a reactor at the Three Mile Island nuclear plant in Pennsylvania and a subsequent radiation leak — the worst civilian nuclear accident in American history — Mr. Carter traveled to the plant to reassure the nation.

The president’s political problems worsened by the middle of his term. In the summer of 1979 he spent 10 days at Camp David, the Maryland presidential retreat, conducting a “domestic summit,” listening to advice from 150 prominent Americans. He returned to Washington and delivered an Oval Office address on what he termed “a crisis of confidence” in the nation. What became known as his “malaise” speech — although he did not use that word — lifted his popularity briefly but came to be derided as preachy and downbeat, seeming to define what many considered the uninspiring tone of his presidency.

Two days after the speech, Mr. Carter asked his entire cabinet to submit resignations. He accepted five. The shake-up set off an uproar in Congress. Some critics, including Democrats, suggested that he had undercut confidence in the government; even Mr. Mondale was so distressed that he briefly contemplated resigning.

Mr. Carter’s response to the criticism was the time-honored device of blaming the news media. From the beginning, there had been antagonism between the Washington press corps and the Carter outsiders. Late in his administration, he held more “town meetings” around the country and began meeting with out-of-town reporters and editors to circumvent the capital news media.

But broadly speaking, “Carter’s message was sacrifice and pain,” Mr. Eizenstat wrote. During an address to the nation on the energy crisis, the president opened by saying, “Tonight I want to have an unpleasant talk with you about a problem that is unprecedented in our history.” When celebrating the creation of the Education Department, he said dolefully, “This thing won’t work as well as you think it will.”

It was not as if his presidency was without successes. Eight months after he took office, he and the leader of Panama, Omar Torrijos, signed treaties obliging the United States to surrender control of the Panama Canal by 1999, settling a longstanding point of friction between the two countries.

Mr. Carter saw the move as an overdue show of American resolve “to deal with the developing nations of the world, the small nations of the world, on the basis of mutual respect and partnership.”

But led by Ronald Reagan, conservatives denounced the treaties as a giveaway. “We built it, we paid for it, it’s ours, and we’re going to keep it,” Mr. Reagan said. Gallup found that 78 percent of Americans opposed the treaties.

Mr. Carter campaigned for the measures in the classic style, cajoling, twisting arms and inviting senators to the White House. He also went over their heads with a publicity blitz aimed at voters. In March 1978, he won with a Senate vote of 68 to 32, one more than the two-thirds required for ratification.

His next foreign affairs triumph came more easily. Mr. Carter signaled early in his presidency that he wished to complete the normalization of relations with China that had started with Nixon’s diplomatic breakthrough. To establish full-fledged embassies and increase trade, Mr. Carter embarked on months of secret, delicate negotiations.

The two nations reached an agreement on the main obstacle, the status of Taiwan, which China regarded as a renegade province. The United States severed diplomatic relations with Taiwan and withdrew its military presence there, but also insisted on continuing arms sales, commercial trade and other ties on an unofficial basis.

Mr. Carter and the Chinese leader, Deng Xiaoping, announced the agreement on Dec. 15, 1978. Some conservatives objected, but the normalization seemed to please most Americans. Formal recognition took place on New Year’s Day 1979. Mr. Deng visited Washington that January.

A Historic Handshake

Mr. Carter’s pursuit of a Middle East peace settlement was an even more momentous venture in personal diplomacy. He invited Prime Minister Menachem Begin of Israel and President Anwar el-Sadat of Egypt to Camp David in September 1978 for what would become 13 days of dramatic negotiations to end decades of conflict between their nations.

The talks began in gloom and discord and almost broke down several times, only to be salvaged by Mr. Carter’s persistence in finding a way to continue. Ultimately, the leaders emerged with what was billed as a “framework for peace.” As the world watched in disbelief, Mr. Carter hosted a White House ceremony with a smiling Mr. Begin and Mr. Sadat.

Mr. Begin and Mr. Sadat returned home to growing dissent, however. The framework projected a peace treaty between Egypt and Israel and self-rule for Palestinians on the West Bank of the Jordan River and in the Gaza Strip. Israel was to return Egyptian territory in the Sinai Peninsula that it had seized in their 1973 war. But negotiations bogged down on the details.

Mr. Carter stepped in again. Mr. Begin returned to Washington for more talks and agreed to break the deadlock. Mr. Carter flew to Cairo to get Mr. Sadat’s approval, then to Jerusalem for Mr. Begin’s final assent for what would be known as the Camp David Accords. While the Palestinian piece of the negotiation would remain unresolved, the image of Mr. Sadat and Mr. Begin shaking hands with a grinning Mr. Carter at the peace treaty signing would become one of the most enduring images of the era.

The agreement brought Mr. Sadat and Mr. Begin the Nobel Peace Prize in October 1978. Mr. Carter, the architect of the settlement, was passed over on a technicality: He had not been nominated in time. He was to wait 24 years for the honor.

One of Mr. Carter’s biggest foreign policy disappointments was his failure to finalize a new Strategic Arms Limitation Talks, or SALT, treaty with the Soviet Union, something he had pledged to do when he took office. The first SALT agreement, signed in 1972, was to expire in 1977.

Negotiations got off to a rocky start. Mr. Carter had criticized human rights violations in the Soviet Union, but he instructed Secretary of State Vance to persist, and on June 18, 1979, in Vienna, the new SALT II treaty limiting each side’s nuclear bombers and missiles was signed by Mr. Carter and the Soviet premier, Leonid I. Brezhnev.

Then, during a bitter, protracted debate about the treaty in the Senate, the issue was suddenly removed from the table by the Soviet invasion of Afghanistan, making approval impossible. On Jan. 3, 1980, Mr. Carter reluctantly asked the Senate to delay the ratification process. It never resumed, and in 1986 President Reagan formally repudiated the treaty.

Mr. Carter later called the failure of the SALT negotiations “the most profound disappointment of my presidency.”

He responded to the invasion by ordering an embargo on sales of grain and high technology to the Soviet Union and by persuading the United States Olympic Committee to boycott the 1980 Summer Games in Moscow. Both actions elicited protests at home, especially from farmers over the grain embargo.

To address human rights, a theme of his Inaugural Address, Mr. Carter hired a group of strong rights advocates led by Ms. Derian, the assistant secretary of state for human rights, who was known for standing up to the segregationist power structure in Mississippi. In her new job, she traveled the world confronting dictators and demanding an end to torture and other abuses.

But Mr. Carter soon learned that change could be difficult. There were tensions over ideology. Some rights advocates wanted to attack the violations of right-wing dictators; others saw the abuses by Communist nations as more pernicious.

The administration ultimately drew back from its confrontation with the Soviet Union over human rights but pursued the campaign in Latin America and Africa, cutting military aid to Argentina, Uruguay and Ethiopia.

How much Mr. Carter advanced the cause of human rights is difficult to gauge. There is no doubt, however, that he made the issue more visible beyond the American borders.

The Hostage Crisis

On Nov. 4, 1979, militant Iranian students seized the United States Embassy in Tehran and took 66 Americans hostage. Thus began the most traumatic episode of the Carter administration.

The hostage crisis had its origins in the Iranian revolution led by the Islamic fundamentalist Ayatollah Ruhollah Khomeini. Mohammed Reza Pahlavi, the shah of Iran and ruler of the country intermittently since 1941, went into exile in January 1979. He lived in Mexico until November, when he was allowed to travel to the United States for cancer treatment.

Mr. Carter had resisted pressure to let the shah into the country. Among those pleading the shah’s case were Mr. Brzezinski, by now the president’s national security adviser; Henry A. Kissinger, Nixon’s secretary of state; and Mr. Rockefeller, the banker.

The president relented only after learning that the shah could not receive the treatment he needed in Mexico, but he foresaw the consequences. “What are you guys going to advise me to do when they overrun our embassy now and take our people hostage?” he asked his aides.

The shah arrived in New York on Oct. 24, 1979. Iranian militants began to demonstrate outside the American Embassy. Days later, about 3,000 of them overran the embassy and seized the hostages with the approval of Ayatollah Khomeini.

Mr. Carter and his advisers began planning a rescue operation as early as the second day of the hostages’ captivity. One plan after another was discarded. To bring pressure on the Iranian ruler, Mr. Carter stopped the purchase of Iran’s oil and froze all Iranian assets in the United States.

Two weeks into their captivity, more than a dozen hostages were released. Six others who eluded the militants and took refuge with the Canadian ambassador were spirited out of the country in a C.I.A. operation later made famous by Ben Affleck in “Argo,” the 2012 movie he directed and starred in.

Mr. Carter continued to negotiate for the remaining 52 hostages through both open and secret channels, but to no avail, and on April 24, 1980, he ordered a military rescue. The mission failed amid a disastrous loss of helicopters and the death of eight soldiers in the Iranian desert. He also lost Mr. Vance, his valued secretary of state, who had counseled against the mission and resigned in protest four days later. Mr. Vance was replaced by Senator Edmund S. Muskie of Maine.

While the public initially rallied behind Mr. Carter, the longer the crisis wore on, the more feckless he appeared. Over the objections of his advisers, he limited his campaigning for re-election and other activities to concentrate on freeing the hostages, ultimately making it look as if his whole presidency had been taken hostage. In their nightly broadcasts, network anchors counted the numbers of days since the hostages had been seized.

“I may have overemphasized the plight of the hostages when I was in my final year,” Mr. Carter told The Washington Post in 2018. “But I was so obsessed with them personally, and with their families, that I wanted to do anything to get them home safely, which I did.”

A new and frantic effort to free the hostages was begun just days before the end of the Carter presidency. Working through a half-dozen foreign capitals, the administration reached a general agreement with Iran, but it snagged on details of releasing Iranian assets held in United States banks.

Mr. Carter’s diary (he talked into a tape recorder at increasingly short intervals during the last days of the crisis) reveals that he was up all night the night before he left office.

He kept President-elect Reagan informed with regular phone calls. Just after 6:47 a.m. on Jan. 20, 1981, Inauguration Day, he had good news to share. All the promised money for Iran was now in an escrow account, and the Bank of England was ready to forward it. “I place a call to Governor Reagan to give him the good news,” Mr. Carter recorded in his diary, “and am informed that he prefers not to be disturbed, but that he may call back later.”

Mr. Carter walked reluctantly to his private quarters to get dressed for Mr. Reagan’s inauguration. Later he wrote, “As I looked at myself in the mirror, I wondered if I had aged so much as president or whether I was just exhausted.”

A little more than a half-hour after leaving the presidency, Mr. Carter learned that the hostages, after 444 days of captivity, had left Iran. It was one final indignity inflicted on him by Tehran, which had delayed their departure until after Mr. Reagan took the oath of office.

The hostage crisis reverberated for years. Some in the Carter camp were convinced that the Reagan campaign had made a secret deal with the Iranians in 1980 to keep the hostages in Tehran until after the election. In his book “October Surprise: America’s Hostages in Iran and the Election of Ronald Reagan” (1991), Gary G. Sick, a specialist on Iran as a member of the National Security Council during the crisis, asserted that William J. Casey, a World War II spymaster and Mr. Reagan’s campaign manager, had promised massive arms shipments to Iran as part of the deal. A congressional investigation produced suspicions but no hard proof, and the Reagan team adamantly denied any such plot.

But last year, more than four decades later, new testimony implicated Mr. Casey. Ben Barnes, a former lieutenant governor of Texas, told The New York Times that he joined a trip to the Middle East in the summer of 1980 with former Gov. John B. Connally of Texas, a Republican hoping to serve in a future Reagan cabinet. According to Mr. Barnes, Mr. Connally told multiple regional leaders to urge Iran to hold the captives until after the American vote. Mr. Connally later reported to Mr. Casey about his trip, Mr. Barnes said. “History needs to know this happened,” he said, explaining why he came forward so many years later.

Campaign ’80

The 1980 election had been a struggle for Mr. Carter. Before facing Mr. Reagan, he was forced to deal with a challenge from Senator Kennedy for the Democratic nomination.

The Carter-Kennedy relationship was chilly from the start. With Mr. Carter sinking in the polls in 1979, Mr. Kennedy announced his candidacy three days after the hostage crisis erupted. He was joined in the primary contests by Jerry Brown, the former (and future) governor of California. But both ran out of steam before the convention in August at Madison Square Garden.

In Mr. Reagan and his running mate, George H.W. Bush, the Democrats faced a formidable ticket. Mr. Reagan, a former actor and California governor, was one of America’s most skilled users of television, and his sunny vision of America as a “shining city on a hill” contrasted with Mr. Carter’s view of a troubled country.

Mr. Reagan pursued a Southern strategy of driving a wedge between the region’s increasingly conservative white voters and a Democratic Party that had shifted to the left on civil rights and other issues. Mr. Reagan kicked off his Southern campaign with a speech at the Neshoba County Fair, just outside Philadelphia, Miss., where three civil rights workers were murdered by the Ku Klux Klan in 1964.

Throughout the campaign, the nation watched the spectacle of Cuban refugees, many of them criminals turned out of jail by President Fidel Castro, flooding into the United States and creating turmoil. Among those upset was the young Democratic governor of Arkansas, Bill Clinton, who would later attribute his own re-election defeat in 1980 to Mr. Carter’s decision to house many of the Cubans at Fort Chaffee, in Mr. Clinton’s state, where they rioted in June.

Another distraction was Mr. Carter’s younger brother, Billy, who had registered as a foreign agent. He had accepted a $220,000 loan from Libya to try to get its oil on the United States market. His financial dealings were investigated by the Internal Revenue Service and the Justice Department, and while no charges were filed, the publicity caused problems for the Carter campaign.

Mr. Carter ignored the third candidate in the race, Representative John B. Anderson, a Republican from Illinois running as an independent, and met Mr. Reagan for a debate in Cleveland on Oct. 28, just a week before the election. The president demonstrated command of the issues, but Mr. Reagan outflanked him with a genial demeanor that belied the warmonger image promoted by Democrats.

When Mr. Carter presented him as a radical right-winger who would gut Medicare and Social Security, Mr. Reagan defused the attack by shaking his head as if in disappointment. “There you go again,” he said.

But along with the Iran hostage crisis, perhaps the most important factor in Mr. Carter’s undoing was the dismal state of the economy. Mr. Reagan turned the “misery index,” which had reached 22 percent, against Mr. Carter and summed up his case at the debate with the cutting question, “Are you better off than you were four years ago?”

The answer for many Americans was no. On Nov. 4, 1980, Mr. Reagan won in a landslide, capturing 489 electoral votes to 49 for Mr. Carter, who won just six states and the District of Columbia. In the popular vote, Mr. Reagan received 51 percent to 41 percent for Mr. Carter; Mr. Anderson finished with 7 percent.

After the White House

Recovering from the voters’ painful rejection, Mr. and Mrs. Carter, in time, began to build a new life. They moved back to Plains to the first and only house they had ever owned, a modest one-story rancher valued in 2018 at just $167,000 — a figure that The Washington Post noted was less than the cost of the armored Secret Service vehicles parked outside day and night.

Shortly after returning to Georgia, the Carters learned that the peanut operation, which had been placed in a blind trust, was in debt by more than $1 million. They sold it to the Archer-Daniels-Midland Company, the farm-products conglomerate, but kept 2,000 acres of farmland, along with their house and its accompanying 170 acres.

The Carters fished, hiked and went to church. Mr. Carter learned to ski at age 62. He climbed Mount Fuji at 70. Both he and Mrs. Carter wrote memoirs, and Mr. Carter went on to write 32 books, mainly extended essays on public policy but also an inspirational volume, “The Virtues of Aging” (1998); a novel, “The Hornet’s Nest” (2003), set during the Revolutionary War; and a children’s book, “The Little Baby Snoogle-Fleejer” (2014), illustrated by his daughter, Amy.

Of all his books, the most controversial was “Palestine: Peace Not Apartheid” (2006), which compared Israel’s treatment of the Palestinians to South Africa’s former system of racial repression. The book generated a backlash among Israel’s supporters, and 14 members of the Carter Center advisory board resigned in protest.

Mr. Carter’s final book, published in 2018 by Simon & Schuster, was “Faith: A Journey for All,” a reflection on the role of faith in his life. He also wrote poetry and taught at Emory University in Atlanta.

But in leaving the White House at age 56, Mr. Carter resolved to do more than write books and build a presidential library. “What Carter really wanted was to find some way to continue the unfinished business of his presidency,” the historian Douglas Brinkley wrote in “The Unfinished Presidency: Jimmy Carter’s Journey Beyond the White House” (1998).

In 1984, the Carters got involved in a well-publicized venture, Habitat for Humanity. They spent one week a year wielding hammers and saws to build houses for the poor, and as of 2019 the former president had helped renovate nearly 4,400 homes in 14 countries with his own tool belt. He also launched an effort to eliminate Guinea worm in Africa, and he taught Sunday school at his local church every other week.

Mr. Carter developed an easy camaraderie with Gerald Ford, and they collaborated on a variety of post-presidential pursuits, including a joint call in 1998 for Congress to censure Mr. Clinton rather than impeach him for lying under oath to cover up his affair with a White House intern. By the time Mr. Ford died in 2006, they had become such good friends that Mr. Ford requested that Mr. Carter speak at a memorial service.

But Mr. Carter had testier relations with other presidents. He fumed that Mr. Reagan had reversed many of his policies on the environment and human rights, and the Carters bristled at never being invited to the Reagan White House for a state dinner. He was a vocal critic of the Iraq invasion of 2003 and called George W. Bush’s administration at the time the “worst in history.”

At the heart of Mr. Carter’s post-presidency was his ambition to be a peacemaker. In 1989, he led a team in monitoring the elections in Panama and denounced them as fraudulent. The next year, he monitored elections in Nicaragua that resulted in the ouster of the Sandinista government, accomplishing at the ballot box what Mr. Reagan had been unable to do on the battlefield with the contra rebels.

In the following years Mr. Carter traveled the globe mediating conflicts in regions from Asia to the Caribbean and pushing to improve global public health and human rights. Mr. Clinton, who had rebounded from his setback in 1980 and captured the presidency in 1992, sent Mr. Carter, Gen. Colin L. Powell and Senator Sam Nunn of Georgia to Haiti in 1994 to persuade a military junta there to restore President Jean-Bertrand Aristide to power. They did.

Throughout his post-presidency, Mr. Carter involved himself in Middle Eastern and arms control issues, sometimes nettling American administrations, both Republican and Democratic. Despite friction over the private diplomacy, Mr. Clinton in 1999 presented Mr. and Mrs. Carter with the Presidential Medal of Freedom, the highest civilian award in the United States.

One of Mr. Carter’s last triumphs of personal diplomacy came when he flew to North Korea in 2010 and obtained the release of Aijalon Mahli Gomes, an American who had been sentenced to eight years of hard labor for entering the country illegally.

In 2002 Mr. Carter received the Nobel Peace Prize “for his decades of untiring effort to find peaceful solutions to international conflicts,” as the citation put it, and used the occasion to warn against invading Iraq. He was one of four American presidents to be awarded the prize, the others being Theodore Roosevelt, Woodrow Wilson and Barack Obama, who were all given the honor while still in office.

Mr. Carter expressed strong disapproval of what he saw as a worrisome turn toward human rights abuses by the United States, even with a fellow Democrat, Mr. Obama, in the White House.

“Revelations that top officials are targeting people to be assassinated abroad, including American citizens, are only the most recent, disturbing proof of how far our nation’s violation of human rights has extended,” he wrote in The Times in June 2012.

Alone among his presidential peers, Mr. Carter initially expressed sympathy for Donald Trump, telling The Times in 2017 that “the media have been harder on Trump than any other president certainly that I’ve known about.” He offered to help the president broker a nuclear agreement with North Korea.

But a year later he had changed his mind, telling The Post that Mr. Trump had been “a disaster.” In a speech in September 2018, Mr. Carter said that if he were president again “the first thing I would do would be to change all of the policies that President Trump has initiated.” He expressed concern about Mr. Trump’s trade war with China, opposed his border wall and supported an impeachment investigation against him.

At one point, Mr. Carter asserted that Mr. Trump “didn’t actually win the election in 2016” and that he had assumed office only with the help of Russia. The comment drew a retort from Mr. Trump, who called Mr. Carter a “terrible president.”

But Mr. Carter later sent a letter to Mr. Trump offering thoughts about China, prompting the incumbent to call him. Afterward, Mr. Trump released a statement saying he had “always liked” Mr. Carter, despite having previously called him the worst president in history.

Mr. Carter chose to sum up his presidency differently, of course. In 2010, in his book “White House Diary,” he quoted his friend and partner Mr. Mondale: “We obeyed the law, we told the truth, and we kept the peace.”

Mr. Carter’s survivors include his four children, 11 grandchildren and 14 great-grandchildren.

Mr. Carter escaped the pancreatic cancer that killed his father and his three younger siblings at relatively young ages. Ruth Carter Stapleton died in 1983 at 54, Billy Carter in 1988 at 51 and Gloria Carter Spann in 1990 at 63.

But he was not immune to another kind of cancer. His doctors had noticed a mass on his liver in the spring of 2015 while examining Mr. Carter after he had returned from a trip to Guyana with a cold.

Announcing his brain cancer at a news conference, he struck many as unusually candid for a former president. Some said he showed both vulnerability and bravery.

That Sunday morning, he showed up at Maranatha Baptist Church in Plains, as promised, to teach Sunday school. Just months later, he announced that after undergoing treatment he was cancer-free.

It was a testament to his resilience, even in advanced age. He repeatedly bounced back from medical troubles. In 2017, he collapsed in Canada while cutting wood on one of his annual Habitat for Humanity projects and was treated for dehydration. He fell and broke his hip in May 2019, then fell two more times that October, the first time requiring 14 stitches and the second time fracturing his pelvis. He was back in the hospital the following month for a procedure to relieve bleeding in his brain.

For all those pointed reminders of his mortality, Mr. Carter expressed no fear of inevitable death.

“I wasn’t afraid or particularly sorrowful, except that I wouldn’t see the people I loved anymore,” he recalled about his bout with cancer in an interview with the presidential historian Mark K. Updegrove in Parade magazine in 2018. “But I didn’t have any feeling of resentfulness or fear, and I was surprised at that. I just felt a particular equanimity about it.”

He lived long enough to see Mr. Biden elected, a special moment given their history; Mr. Biden had been the first senator to endorse Mr. Carter’s bid for the White House. When Mr. Carter was not well enough to attend the inauguration, Mr. Biden made a point of visiting him in Georgia weeks later.

In the four decades since Mr. Carter left the White House, no other sitting president had paid him the respect of coming to see him in Plains, making Mr. Biden’s visit something of a symbolic embrace that reflected evolving views of the defeated president-turned-elder-statesman.

“He showed us throughout his entire life what it means to be a public servant, with emphasis on the word servant,” Mr. Biden said in a video tribute issued at that time. Addressing his predecessor, Mr. Biden added: “President Carter, you’ve shown us what we can be as individuals, as a nation — courageous, compassionate and humble.”

Excerpts: The New York Times.