In the 246-year history of the United States, no sitting president has turned 80 while in the Oval Office. That will change on Sunday, when President Joe Biden celebrates his birthday.
Mr Biden enters his 81st year on a high after his Democratic colleagues performed better than expected in November’s midterm elections, keeping control of the Senate and only narrowly losing the House of Representatives.
It is a feat few presidents have achieved, and some experts believe the unexpected results may help to shift how history will view him.
“He has, I think, a fairly strong legislative record, an overperformance in the midterm elections across the board and then finally, in terms of the direction of his agenda, it's still intact,” said Thomas Balcerski, a presidential historian and visiting professor at Occidental College in Los Angeles, California.
Mr Balcerski said that at the halfway point of his first term, “Biden looks great”, especially compared to the “prior administration”.
From one of the youngest senators to the oldest president
Mr Biden’s presidency is the latest act in a political career that has spanned more than five decades.
He grew up in Scranton, Pennsylvania, an impoverished town in the north-east corner of the state.
His father, Joe Sr, lost his job when Mr Biden was young and he spent his formative years in a modest three-storey white clapboard home that his family shared with his maternal grandparents.
Mr Biden has often leaned on his early financial hardship to try to connect with the working class.
“I understand that many of my fellow Americans view the future with fear and trepidation,” he said in his inauguration speech.
“I understand they worry about their jobs. I understand, like my dad, they lay in bed at night, staring at the ceiling, wondering, can I keep my health care? Can I pay my mortgage? Thinking about their families, about what comes next. I promise you, I get it.”
Mr Biden was first elected to the Senate in 1972, when he was 29 years old, making him the sixth-youngest senator in history, according to the Senate Historical Office.
Weeks after Mr Biden earned the trust of his adoptive home state of Delaware to represent them in Washington, his life dramatically changed.
His first wife, Neilia Hunter Biden, and their three young children were in a car accident.
Ms Biden and their one-year-old daughter Naomi were killed; their two young sons Hunter and Beau survived but suffered serious injuries.
Days after the accident, with his two boys still in hospital, Mr Biden was sworn in to the US Senate.
He took his oath in their hospital room and pledged to always put them first.
“I make this one promise, that if in six months or so there’s a conflict between my being a good father and being a good senator, which I hope will not occur, I promise you that I will call Governor Elect Tribbitt as I had earlier and tell him that we can always get another senator but they can’t get another father,” he said.
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Mr Biden went on to serve for 36 years in the Senate and only left in 2008, when Mr Obama, a young senator from Illinois, picked him to be his running mate for his White House race.
Over the past five decades, he has built a nearly unprecedented career in Washington.
“It's hard for people to be in office for that long and not develop some baggage and dirty laundry and things that voters will hold against them," Lindsay Chervinsky, a presidential historian, told The National.
His career has not been without failure and controversy: in 1988, he made his first run for the White House, but a plagiarism incident derailed his hopes of winning the Democratic primary, which was eventually won by Michael Dukakis.
But he continued holding high-ranking positions within the Senate, including serving on the Judiciary Committee and the Foreign Relations Committee.
Ms Chervinsky likened his longevity to John Quincy Adams, the sixth US president, whose career started when he was only 12, serving as secretary to foreign delegations in Europe and included ambassadorships and a Senate seat.
'I feel good,' President Joe Biden says after midterms — video
Through it all, she said, Mr Biden has kept his finger on the pulse of the Democratic Party.
“He has a really good nose for where the centre of the Democratic Party is,” Ms Chervinsky said.
“He's not afraid to be in that centre and he's not afraid to evolve and shift and change over time.”
That fundamental understanding of his party and its base, coupled with a “compelling personal story” has helped Mr Biden score favourably on the Siena College Research Institute’s (SCRI) Survey of US Presidents.
Mr Biden came in 19th on the list after his first year, far ahead of former president Donald Trump and only slightly behind Mr Obama.
“He does pretty well on his overall background coming in as the 15th highly rated president,” said Don Levy, director of the survey. “I think that goes overwhelmingly to his decades of public service.”
But the president scored poorly in his ability to communicate and his leadership strengths, Mr Levy said.
This is clear from approval polls, which show Mr Biden's popularity remains stuck at less than half of voters.
Mr Biden inherited a country in the grips of a global pandemic and in deep division, highlighted by the attack on the US Capitol on January 6, 2021.
These adverse circumstances may ultimately help history view his presidency more favourably.
“The country, to some extent, is in a crisis period right now and should Joe Biden steer this ship to a point where that threat to democracy is behind us, to where the hyper-partisanship somehow is diffused, to the point where people can disagree but pass meaningful legislation, then Biden has an opportunity to move up the rankings,” Mr Levy told The National.
Biden receives Covid vaccine — in video
His path to legislative success has just become a lot more difficult, however, with Republicans taking control of the House, meaning the former senator will have to rely more on his ability to compromise to push his agenda forward.
Looking ahead to 2024, the biggest question is whether he will want to run for a second term at age 82.
His age has long been considered a weakness on the campaign trail but Mr Balcerski believes that he has helped show the country that “80 years old today isn’t what it used to be.”
Still, his every misstep and gaffe is used by some in the right-wing media as proof of his inability to lead.
His age may not be much of a factor, however, if Mr Trump, who is only about four years his junior, wins the Republican nomination.
“I just think that actually benefits Biden and he would relish a second chance to run against Donald Trump,” Mr Balcerski told The National.
A weekend of celebration
Mr Biden’s birthday will not be the biggest celebration at the White House this weekend.
On Saturday, the president’s eldest grandchild Naomi, named after his deceased daughter, will marry fiancé Peter Neal on the South Lawn.
“No parent or grandparent looks better than on his daughter or granddaughter’s wedding day and it just sort of puts a positive glow on the relationship,” explained Mr Balcerski.