Jimmy Carter, the 39th president of the United States, a broker of peace in the Middle East in his time, and a tireless advocate for global health and human rights, has died, it was announced on Sunday. He was 100 years old.

“My father was a hero, not only to me but to everyone who believes in peace, human rights, and unselfish love,” said Chip Carter, the former president’s son, in a statement.

“My brothers, sister, and I shared him with the rest of the world through these common beliefs. The world is our family because of the way he brought people together, and we thank you for honoring his memory by continuing to live these shared beliefs.”

A Georgia Democrat, Carter was the longest-lived president in US history. He only served one term in the White House and was soundly beaten by Ronald Reagan in 1980. But Carter spent the decades afterward focused on international relations and human rights, efforts that won him the Nobel peace prize in 2002.

Carter had undergone a series of hospital stays before and his family said on 18 February last year that he had chosen to “spend his remaining time at home”, in hospice care and with loved ones. The decision had “the full support of his family and his medical team”, a family statement said.

President Joe Biden on Sunday declared 9 January a national day of mourning, calling on Americans to visit their places of worship to “pay homage” to the late US leader.

Carter’s wife, Rosalynn Carter , died last November, two days after her own transition to hospice care. The former first lady was 96. The pair married in 1946 and the former president attended her memorial service, traveling from the couple’s longtime home in Plains, Georgia, to the Glenn Memorial church in Atlanta.

The Carters’ eldest grandchild, Jason Carter, had said in a media interview in June this year that the former president was not awake every day but was “experiencing the world as best he can” as his days were coming to an end .

Carter took office in 1977 as “Jimmy Who?”, a one-term Georgia governor and devout Christian whose unfamiliarity with Washington was seen as a virtue after the Watergate and Vietnam war years.

Hopes for the Carter presidency were dashed, however, by economic and foreign policy crises, starting with high unemployment and double-digit inflation and culminating in the Iran hostage crisis and the Soviet invasion of Afghanistan. A rolling energy crisis saw the price of oil triple from 1978 to 1980, leading to lines at US gas stations .

Such struggles belied early promise. In 1977, Carter completed a treaty that had eluded his predecessors to return control of the Panama canal to its host country. At Camp David in 1978, Carter brought together the Israeli prime minister, Menachem Begin, and the Egyptian president, Anwar Sadat, for a deal that would produce peace that endures today.

Carter’s fruitless attempts to halt the economic slide led Republicans to label him “Jimmy Hoover”, after the Depression-era president. But as Carter prepared to run for re-election in 1980, it was the Iran hostage crisis that weighed most visibly on Americans’ minds, the TV anchor Ted Koppel devoting his broadcast five days a week to the plight of 52 Americans held in Tehran. A botched rescue attempt left eight US servicemen dead and fed doubts about Carter’s leadership.

Reagan, a former California governor, won 44 states. The hostages were released on 20 January 1981, hours after Carter left office, prompting speculation that Republicans had made a deal with Iran.

Broadly unpopular then, Carter went on to become not just the longest-lived president but also to have one of the most distinguished post-presidential careers. He was awarded the Nobel peace prize for “decades of untiring effort” for human rights and peacemaking. His humanitarian work was conducted under the Atlanta-based Carter Center, which he founded in the early 1980s, with Rosalynn.

Carter traveled the world as a peace emissary, election observer and public health advocate. He made visits to North Korea in 1994 and Cuba in 2002. The Carter Center is credited with helping to cure river blindness, trachoma and Guinea worm disease, which went from millions of cases in Africa and Asia in 1986 to a handful today.

Carter was a critic of the 2003 invasion of Iraq, drone warfare, warrantless government surveillance and the prison at Guantánamo Bay. He won admiration, and loathing, for his involvement in efforts for Middle East peace, urging a two-state solution in speeches and books including Palestine: Peace Not Apartheid .

He met Shimon Peres, then president of Israel, on a 2012 trip to Jerusalem, but top Israeli leaders generally shunned Carter after publication of the book. As recently as 2015, requests to meet the prime minister and president were rebuffed .

Carter played a central role in promoting Habitat for Humanity, which provides housing for the needy, and was an alternative energy pioneer, installing solar panels on the White House. (Reagan removed them.)

The Carters had four children and 11 grandchildren, among them James Carter IV, credited with playing a pivotal role in the 2012 election when he unearthed a video of Mitt Romney casting aspersions on 47% of Americans .

James Earl Carter Jr grew up in Plains, Georgia, a town of fewer than 1,000 and about 150 miles south of Atlanta. A graduate of the US Naval Academy, he rose to the rank of lieutenant and worked on the nascent nuclear submarine program. After his father’s death in 1953, he took up peanut farming. He was elected to the Georgia senate then won the governorship in 1970, calling for the state to move beyond racial segregation.

Carter’s blend of moral authority and folksy charisma produced moments of unusually frank national dialogue. In a 1979 speech, he spoke semi-spontaneously for half an hour about a “crisis of confidence” – “a fundamental threat to American democracy … nearly invisible in ordinary ways”. Americans had fallen into a worship of “self-indulgence and consumption”, he said, only to learn “that piling up material goods cannot fill the emptiness of lives which have no confidence or purpose”.

The address struck a chord: Carter’s popularity surged 11 points. But after Reagan and others recast it as a self-indulgent exploration of personal malaise, the speech became a liability.

James Fallows, a former Carter speechwriter, wrote in 1979 that the president suffered from an inability to generate excitement but “would surely outshine most other leaders in the judgment of the Lord”.

Carter outlived the two presidents who followed him, Reagan and George HW Bush.

There will be public observances in Atlanta and Washington DC, followed by a private interment in Plains, Georgia. Carter’s state funeral, including all public events and motorcade routes, is still pending.