Amid a devastating global pandemic and the threat of possible domestic terrorism, Joe Biden was sworn-in as the 46th president of the United States Wednesday shortly before noon, pledging to unite the country and calling on Americans to end the "uncivil war" that has fractured the nation.
In a ceremony that kept with tradition while being unlike any other inauguration in U.S. history, Biden took his oath of office before a small, socially distanced audience in a city that has been locked down because of the dual threats of COVID-19, which has killed over 400,000 people in the U.S., and worries over another attack just two weeks after the deadly riot at the Capitol.
In an impassioned address, Biden repeatedly stressed the need for unity, calling it the only "path forward."
"I know speaking of unity can sound to some like a foolish fantasy these days, I know the forces that divide are deep and they are real," he said. "Our history has been a constant struggle between the American ideal that we're all created equal and the harsh ugly reality of racism, nativism, fear, demonization."
"This is our historic moment of crisis and challenge — and unity is the path forward," he said.
"The answer is not to turn inward, to retreat into competing factions, distrusting those who don't look like you or worship the way you do, or don't get their news from the same sources you do," the president added a moment later.
"We must end this uncivil war that pits red against blue, rural versus urban, conservative versus liberal. We can do this if we open our souls instead of hardening our hearts. If we show a little tolerance and humility, and if we're willing to stand in the other person's shoes," he continued.
Biden vowed to move quickly to address the pandemic, the subsequent economic collapse, racial justice, climate change and political extremism.
He also repudiated the mob that had attacked the Capitol two weeks ago and promised he would be president for all Americans, including those who didn't vote for him.
"With unity we can do great things, important things. We can right wrongs. We can put people to work in good jobs, we can teach our children in safe schools, we can overcome the deadly virus," he said. "We can deliver racial justice and we can make America once again a leading force for good in the world."
Temperatures were in the low 40's in the nation's capital, with strong winds. Snow flurries dotted the air as Biden took to the lectern.
While Biden did not once mention Donald Trump by name, his 21-minute speech served as a powerful rebuttal of his predecessor.
Biden’s refutation of Trump was especially apparent when he, in the opening words of his speech, reflected on the fragility of democracy, and indirectly referred to how Trump’s efforts to subvert the results of the 2020 election nearly shattered the country.
"Today we celebrate the triumph not of a candidate, but of a cause, the cause of democracy,” he said."We've learned again that democracy is precious. Democracy is fragile, and, at this hour, my friends, democracy has prevailed."
As is tradition, the chief justice of the United States, John Roberts, administered the oath of office to Biden just before the clock struck 12. Biden took the oath with his hand on top of his 127-year-old, 5-inch-thick family Bible, which will be held by his wife, Jill Biden.
Moments earlier, Kamala Harris was sworn in as the first woman, the first Black American and the first South Asian Americanvice president by Justice Sonia Sotomayor, the first Latina member of the Supreme Court.
At 78, Biden is the oldest president to take office. And with his inauguration coming just two weeks to the day after a violent mob of Trump supporters stormed the Capitol, the stakes for his inaugural address couldn't have been much higher.
His swearing-in cemented Democratic control of the White House and both chambers of Congress. That, however, isn't likely to make Biden's job any easier. Democrats hold a razor-thin majority in the House, and their control of the 50-50 Senate is only thanks to Harris' ability to cast a tie-breaking vote as vice president.
In attendance at the scaled-down ceremony were most members of Congress and the Supreme Court and former presidents Barack Obama, George W. Bush and Bill Clinton, and their spouses, as well as Vice President Mike Pence.
Among those who were not present was President Donald Trump, making him the first president to skip his successor's inauguration in more than 150 years. As he left the White House on Wednesday morning, he told reporters that serving as president was "the honor of a lifetime" and claimed that "we've accomplished a lot."
Trump and first lady Melania Trump then participated in a send-off ceremony before a small group at Joint Base Andrews, in Maryland, where the outgoing president said about his exit, "hopefully, it's not a long-term goodbye."
"We will be back in some form," Trump said. "We were not a regular administration."
Trump, who spent months falsely claiming that the 2020 election was stolen from him, also wished his successors good luck — although he never referred to Biden or Harris as the president or vice president.
"I wish the new administration great luck and great success. I think they'll have great success. They have the foundation to do something really spectacular," he said.
Trump then boarded Air Force One for one final trip down to his Mar-a-Lago resort in southern Florida.
He left Biden a note before he left the White House, as is custom, the White House said. The contents have not been made public.
Because of the pandemic, attendees will be socially distanced and will have to wear masks. Only about 1,000 people will attend, the Joint Congressional Committee on Inaugural Ceremonies has said. In normal times, the committee makes 200,000 tickets available for members of Congress.
Extra security precautions stemming from the Capitol attack include over 25,000 National Guard members who were called up to keep the event secure and extra security fencing erected near the Capitol. In addition, the White House and numerous streets have been shut down.
The National Mall, usually a place for onlookers to gather, was also closed — instead dotted with flags to represent Americans watching from home as the public was not invited to attend this year’s ceremony due to COVID-19. Even the lawn at the base of the Capitol, typically reserved for elected officials and their guests, was restricted to a limited number of people this year.
Inside the West Wing earlier Wednesday, White House residence staffers and Secret Service agents appeared to be starting the well-choreographed, yet frantic, changeover from one administration to the next. The process was even more taxing this year, since workers won’t have the usual amount of time afforded, given the cancellation of the inaugural luncheon and traditional in-person parade.
Following the inaugural ceremony, Biden and Harris participated in a wreath-laying ceremony at the Tomb of the Unknown Soldier in Arlington, before receiving an official escort to the White House. Once there, Biden is scheduled to immediately begin signing executive orders designed to undo many of the hallmarks of Trump's tenure.
Those will include measures to rejoin the Paris Agreement on climate change, repeal Trump's restrictions on travel from several Muslim-majority countries, stop construction of the Southern border wall and mandate wearing masks on federal property.
He will also use his first day in office to propose a sweeping immigration reform bill, a lofty legislative task his administration has decided to take on from the start.
Adam Edelman reported from New York. Lauren Egan reported from Washington, D.C.
This story first appeared on NBCNews.com.