The highest death toll from coronavirus in the world and an economic fallout leaving millions jobless has compounded the turmoil of a bitterly-divided nation where democracy itself at times seemed in jeopardy.
It falls to Joe Biden to begin a repair job on a gargantuan scale when he enters the White House as the 46th president of the United States on Wednesday.
The Democratic former vice-president to Barack Obama pitched his campaign as a “battle for the soul” of the nation and has been known for reaching across the divide to seal bipartisan agreement during his career in Congress.
Joe Robinette Biden Jr, who at the age of 78 will become the oldest president to take office, was born in Pennsylvania in 1942 to a Catholic family that can trace its roots back to Ballina, Ireland, from where his great, great, great grandfather – Edward Blewitt – left for America during the famine.
Mr Biden earned a law degree from Syracuse University in 1968 and four years later began his first of six terms as a senator for the state of Delaware, being elected in 1972 as the sixth youngest senator in US history at the age of 30.
But his entry into Congress was marred by the darkest of tragedies.
Just weeks after the election, his first wife Neilia was at the wheel of the family’s Chevy station wagon with their three children as they returned from buying a Christmas tree.
A tractor smashed into the car’s side, killing Neilia and baby Naomi. Hunter, then two, sustained a head injury and three-year Beau was treated in hospital with broken bones.
Mr Biden took the oath of office from their hospital room.
“For the first time in my life, I understood how someone could consciously decide to commit suicide,” he later said.
But “the bigger the highs, the deeper the troughs” he would say and he found tactics for coping with his grief, raising his two boys as he rose in seniority in the Senate.
He met Jill Jacobs on a blind date in 1975 and married the aspiring teacher two years later. They had a daughter, Ashley, in 1981.
His first attempt at the White House was in 1988 but he was forced to withdraw from the Democratic nomination contest after he admitted to plagiarising parts of a speech from British Labour leader Neil Kinnock.
The year before, Mr Kinnock said in a conference speech: “Why am I the first Kinnock in a thousand generations to be able to get to university?
“Was it because all our predecessors were thick?”
Without crediting the MP, Mr Biden echoed on the campaign trail: “Why is it that Joe Biden is the first in his family ever to go to a university?
“Is it because our fathers and mothers were not bright?”
Mr Biden continued in the Senate, where his record has come under intense scrutiny from modern-day progressives.
He failed to ensure Anita Hill’s sexual harassment allegations were fairly examined while overseeing the confirmation hearings of Supreme Court nominee Clarence Thomas.
He played a role drafting a sweeping crime bill blamed for contributing to mass incarceration, voted for deregulation of Wall Street and the war in Iraq.
He also worked with segregationist senators in the 1970s, with a joke during a 2019 fundraiser about one having “never called me ‘boy’, he always called me ‘son'” leading to widespread criticism because of the comment’s racial undertones.
His second run for the Democratic candidacy, in 2007, concluded with him pulling out and joining the Obama ticket, going on to be the deputy for the first black president, his loyalty being rewarded with the Presidential Medal of Freedom with Distinction.
They were seen as having a close friendship, almost brotherly, during the two terms and Mr Obama described him as the “best vice president America ever had”.
Mr Biden voiced support for LGBT rights, beating the president to the endorsement of same-sex marriage when he said he was “absolutely comfortable” with the idea in 2012.
He was also key in getting the Affordable Care Act, which secured health insurance for millions of Americans, through Congress.
Personal tragedy struck Mr Biden again, in 2013, when his son Beau was diagnosed with a brain tumour.
Consistently ranked as one of the least well-off senators, he planned to take out a second mortgage to cover his son’s mounting bills.
“Don’t do that,” Mr Obama said. “I’ll give you the money. I have it. You can pay me back whenever.” Mr Biden did not take him up on the offer.
Beau died in 2015 at the age of 46.
Health care is intensely personal to Mr Biden, once saying with regard to his son’s terminal diagnosis: “I can’t fathom what would have happened if the insurance companies had the power to say ‘last few months, you’re on your own’.”
After years of watching the chaos of Donald Trump’s White House, Mr Biden entered the race for the Democratic nomination for a third time, securing the endorsement when his final competitor, Bernie Sanders, dropped out in April.
In the post-Me Too era, Mr Biden did not just face uncomfortable questions about Ms Hill. He was accused by former staff member Tara Reade of sexual assault, though Mr Biden and his campaign team have strongly denied the allegation.
The race for the White House was often brutal, with the Republican labelling his opponent “sleepy Joe” as he tried to portray the man three years his senior as senile.
Covid-19 gripped the nation and it was only exacerbated by Mr Trump’s erratic response. The death toll this month exceeded 360,000.
America also faced a reckoning for racism in its history and present when George Floyd, a black man, died at the hands of three police officers in Minnesota in scenes that horrified the world.
Protests gripped the nation while Mr Trump fanned the flames.
Mr Biden selected Kamala Harris as his running mate, she would become the first black person – and woman – to be elected to the role.
When the nation went to the polls on November 3 the atmosphere was febrile, with genuine fears of heavily armed militias on the streets.
The race was tighter than the pollsters predicted but as Mr Biden appeared to be on course for victory, his opponent fouled the air by falsely claiming victory and making baseless allegations that he was the victim of a massive electoral fraud aided by the huge uptick in postal votes because of the pandemic.
Meanwhile, Mr Biden was calling for calm, telling supporters: “It ain’t over until every vote is counted, every ballot is counted.”
The Republicans mounted legal bids to overturn the result in numerous swing states but each was dismissed, and after the counting was in Mr Biden had made major gains for the Democrats.
His victory was cemented on November 7 when he clinched the key battleground of Pennsylvania, having turned Georgia blue and returning states previously lost to Mr Trump back to the Democratic fold.
In a speech in his hometown of Wilmington, Delaware, Mr Biden said: “I pledge to be a president who seeks not to divide, but to unify.
“And who will work with all my heart to win the confidence of all of you, and for that, I believe, is what America is all about.”
More moderate than some of the Democratic opponents he beat, there was optimism that Mr Biden may have what it takes to heal the nation.
But Mr Trump has gone about making that task as hard as possible, stoking tensions to the point of fever pitch when he urged a mob of loyalists to march on the Capitol on January 6.
They did just that and mounted what approached an insurrection, fighting with police when they stormed Congress in an attempt to overturn the election as lawmakers were confirming Mr Biden’s victory.
Five people died as a result of the siege, including one Trump supporter who was shot by police and a Capitol police officer.
Cementing his notoriety in the history books, Mr Trump became the first president to be impeached twice when some Republicans voted with House Democrats on a charge of inciting insurrection.
He could be prevented from ever holding public office again if more lawmakers from his own party back his conviction during a Senate trial.
Mr Biden will need to live up to every bit of his acclaimed prowess for reaching across the divide and to his passion for improving the health prospects of ordinary Americans after he is inaugurated on Wednesday and he inherits a nation that has been ripped through by Covid-19 and is in perhaps its most divided state since the civil war.