Joe Biden declared that “democracy has prevailed” after he was sworn in as the 46th president of the United States.
Mr Biden’s inauguration came at a time of national tumult and uncertainty at a US Capitol battered by an insurrectionist siege just two weeks ago.
He said: “The will of the people has been heard, and the will of the people has been heeded. We’ve learned again that democracy is precious and democracy is fragile. At this hour, my friends, democracy has prevailed.
“This is America’s day. This is democracy’s day. A day in history and hope, of renewal and resolve.”
The president then turned to challenges ahead, acknowledging the surging coronavirus virus that has claimed more than 400,000 lives in the United States.
Mr Biden, in his third run for the presidency, staked his candidacy less on any distinctive political ideology than on galvanising a broad coalition of voters around the notion that Mr Trump posed an existential threat to American democracy.
Mr Biden did not mention Mr Trump by name in his inaugural address but alluded to the rifts his predecessor had helped create.
Mr Biden said: “I know the forces that divide us are deep and they are real. But I also know they are not new. Our history has been a constant struggle between the American ideal that we all are created equal and the harsh, ugly reality of racism, nativism, fear, demonisation that have long torn us apart.
Mr Biden came to office with a well of empathy and resolve born by personal tragedy as well as a depth of experience forged from more than four decades in Washington.
Aged 78, he is the oldest president inaugurated.
More history was made at his side, as Kamala Harris became the first woman to be vice president.
The former US senator from California is also the first black person and the first person of South Asian descent elected to the vice presidency and will become the highest-ranking woman ever to serve in government.
President Biden, tweeting from the newly transferred @POTUS Twitter account, said:
Mr Biden and first lady Jill Biden departed the platform at the Capitol following a ceremony that included musical performances from pop stars Lady Gaga and Jennifer Lopez and country singer Garth Brooks.
Celebrated poet Amanda Gorman read a piece noting that, “while democracy can be permanently delayed, it can never be permanently denied”.
Mr Biden is expected to make his first official arrival at the White House as president before a virtual inaugural parade.
Flouting tradition, Donald Trump departed Washington on Wednesday morning ahead of the inauguration rather than accompany his successor to the Capitol.
Though three other former presidents — Bill Clinton, George W Bush and Barack Obama — gathered to watch the ceremonial transfer of power, Mr Trump, awaiting his second impeachment trial, instead flew to Florida after stoking grievance among his supporters with the lie that Mr Biden’s win was illegitimate.
Mr Trump did adhere to one tradition and left a note for Mr Biden in the Oval Office, according to the White House, which did not release its contents.
And Mr Trump, in his farewell remarks, hinted at a political return, saying: “We will be back in some form.” And he, without question, will shadow Mr Biden’s first days in office.
Mr Trump’s second impeachment trial could start as early as this week. That could test the ability of the Senate, poised to come under Democratic control, to balance impeachment proceedings with confirmation hearings and votes on Mr Biden’s cabinet choices.