(CNN) President Joe Biden ended his first day in office with a note of hope and optimism, closing his inaugural activities with an appearance at the Lincoln Memorial on Wednesday night, where he asked the nation to answer his call for unity, saying it will require "us to come together in common love that defines us as Americans."
"We've learned again that democracy is precious. Because of you, democracy has prevailed," Biden said, alluding to the insurrection at the US Capitol on January 6, which was incited by former President Donald Trump's lies about a stolen election but which did not stop a peaceful transfer of power on Wednesday.
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But Biden noted that the nation is facing myriad challenges, including the pandemic, the recession, last year's calls for racial justice and equality after the police killing of George Floyd, the climate crisis and the attack on the country's system of government two weeks ago.
"The question is: Are we up to it?" the President asked. "Will we meet the moment like our forbearers have? I believe we must and I believe we will. You the American people are the reason why. I've never been more optimistic about America than I am this very day. There isn't anything we can't do if we do it together."
After Trump had refused to formally concede or host Biden at the White House in the morning, Biden and his family walked onto the White House grounds for the first time since he won the election Wednesday afternoon, as did Kamala Harris -- who made history Wednesday when she was sworn in as the first female, the first Black and first South Asian vice president of the United States.
Just hours after he was inaugurated as the 46th President, Biden signed 17 executive actions to begin overhauling the nation's approach to the coronavirus pandemic -- including instituting a mask mandate for federal buildings and inter-state travel -- and undoing some of the Trump administration's most controversial policies, like rejoining the Paris climate accord and rescinding Trump's ban on travelers from predominantly Muslim countries.
Biden told reporters he was starting his term "keeping the promises" he'd made, as he sat at the Resolute Desk Wednesday evening. But he noted that the nation has "a long way to go" and that Congress would need to pass legislation to follow through on his priorities, which include a $1.9 trillion Covid-19 relief bill.
Later that evening, the US Senate confirmed Biden's first nominee, Avril Haines as director of national intelligence, in bipartisan fashion -- approving the nominee 84-10.
White House press secretary Jen Psaki, during her first press briefing, gingerly sidestepped questions about Trump's looming impeachment trial in the Senate, which could complicate efforts to quickly confirm Biden's nominees and take up his legislative priorities.
When asked whether Democratic leaders in the Senate should drop the trial, Psaki said that Biden is focused on the "importance of unity and bringing the country together," adding that the President would defer to Senate leaders on questions of timing.
Harris -- who is now the tie-breaking vote in a Senate that is divided evenly between Democrats and Republicans -- swore in three incoming senators as one of her first acts in her new role. She administered the oath of office to Alex Padilla, who will replace Harris as the junior senator from California. She also swore in Georgia Democrats Jon Ossoff and Raphael Warnock, who won hard-fought runoff races that flipped control of the Senate, giving Democrats control of Congress and the White House.
Trump had left Washington Wednesday morning, becoming the first president in 150 years to boycott his successor's inauguration. But he left a letter for Biden, which, during the new President's brief exchange with reporters Wednesday, he described as "generous" but whose contents he said he would not reveal until he spoke with Trump.
Biden took his oath of office at the US Capitol just two weeks after a mob of insurrectionists invaded that building seeking to overturn the presidential election. The new President set out on the daunting task of uniting the nation by urging Americans to come together as they confront the deadly pandemic, an economic collapse that has left millions unemployed and deep divisions over issues of racial justice and police brutality.
"Today on this January day, my whole soul is in this — bringing American people together, uniting our nation, and I ask every American to join me in this cause," Biden said in his inaugural speech.
The new President set that tone of unity, calm and comity from the top down on a carefully choreographed day that was striking after the chaos and tumult of the past four years under Trump. The former President poisoned already strained relations between the two political parties in Washington, as he lashed out at his political opponents and anyone who dared to criticize him.
But that cloud over Washington had notably lifted, at least for the day, Wednesday as members from both parties mingled at the Capitol during the ceremonies. Outgoing Vice President Mike Pence, who attended the inauguration and skipped Trump's farewell ceremony, and his wife Karen even shared a laugh with Harris and her husband, Doug Emhoff, on the steps of the Capitol before they departed to begin their private lives.
Biden also made it clear that he would not accept infighting, even within his own ranks when he swore in his new staff Wednesday evening.
"If you're ever working with me and I hear you treating another colleague with disrespect, talking down to someone, I will fire you on the spot," Biden told his new employees in a virtual address. He said he believes everyone deserves to be treated with dignity and decency, which he said had been "missing in a big way the past four years."
During his inaugural speech, Biden, who decided to run for the White House after Trump's shocking reaction to the White supremacist rally in Charlottesville, Virginia, in 2017, noted that the nation is struggling through a rise of White nationalism, racism and deep political divisions.
"Politics doesn't have to be a raging fire destroying everything in its path," Biden said, calling on Americans to come together. "We have to be different than this. America has to be better than this."
"I will be a president for all Americans," Biden said speaking directly to those who did not support him in the November election. "I will fight as hard for those who did not support me as those who did."
Biden reflected on the siege in the Capitol several times during his speech, noting that the world is watching after its entire system of government come under attack.
"Here is my message to those beyond our borders: America has been tested and we've come out stronger for it. We will repair our alliances and engage with the world once again. Not to meet yesterday's challenges, but today's and tomorrow's challenges," Biden said.
The new President also said the nation's success in getting through this moment will hinge on whether Americans can come together and set aside their differences to defeat the pandemic that has ravaged the nation, costing more than 400,000 lives. He highlighted some of the previous challenges the nation has confronted, including the Great Depression, two world wars and the September 11 attacks.
"I know speaking of unity can sound to some like a foolish fantasy these days; I know the forces that divide us are deep and are real, but I also know they are not new," Biden said in his speech, calling on Americans to forge a new way forward. "We can see each other not as adversaries, but as neighbors —speaking to each other with dignity and respect. We can join forces, stop the shouting and lower the temperature. Without unity there is no peace, only bitterness and fury; no progress, only exhausting outrage; no nation, only a state of chaos."
He asked his audience to unite to meet the moment as one nation: "If we do that, I guarantee you, we will not fail."
"At this time, in this place, let's start afresh," Biden said.
After a tumultuous year that began a new chapter of the civil rights movement as Americans took to the streets to protest against racial injustice and police brutality after the death of George Floyd, Biden noted that the swearing in of his vice president was a remarkable achievement for a country that has often struggled to live up to its ideal of equality for all.
"Here we stand looking out on the great Mall, where Dr. (Martin Luther) King (Jr.) spoke of his dream. Here we stand where 108 years ago, at another inaugural, thousands of protesters tried to block brave women marching for the right to vote. Today, we mark the swearing-in of the first woman in American history elected to national office, Vice President Kamala Harris," Biden said.
In another ceremony highlight, the nation's first youth poet laureate, Amanda Gorman, recited a poem about bridging divides that she finished on the night that Trump's supporters stormed the Capitol.
"Somehow we've weathered and witnessed a nation that isn't broken, but simply unfinished," Gorman said in the poem she read after Biden's speech. "We've seen a force that would shatter our nation rather than share it. Would destroy our country if it meant delaying democracy. And this effort very nearly succeeded. But while democracy can be periodically delayed, it can never be permanently defeated."
Biden's tone at his inaugural speech could not have been more different than the bitter, divisive one adopted by Trump throughout his presidency in his speeches and tweets, which were threaded with lies and threats that whipped up his crowds and ultimately led to the insurrection at the Capitol earlier this month.
The former president left the White House as president for the last time Wednesday morning, flying to Florida with first lady Melania Trump. On his way out of the Washington area, Trump -- who was not wearing a mask -- again used the racist term "China virus" to describe the coronavirus, describing it in the past tense, and touted his administration's work on developing a vaccine.
He thanked his staff and family and wished the next administration "great success" but did not mention his successor by name.
"We love you, this has been an incredible four years," Trump said in unscripted remarks at Joint Base Andrews shortly before leaving for Florida. "We've accomplished so much."
"I will always fight for you. I will be watching. I will be listening."
Biden's task has been complicated by the fact that Trump impeded the transition between administrations. But Trump left the White House as a disgraced and diminished figure. CNN's White House team has reported that although dozens of current and former officials had been invited to the Wednesday morning farewell ceremony, many declined to attend. Pence said his final goodbyes to Trump on Tuesday.
In a show of unity and Biden's intent to work with leaders from both parties, his first public appearance Wednesday was at a church service at the Cathedral of St. Matthew the Apostle in DC ahead of the inaugural ceremonies with Senate Majority Leader Mitch McConnell, Senate Minority Leader Chuck Schumer, House Speaker Nancy Pelosi and House Minority Leader Kevin McCarthy.
After Biden was sworn in, he went to Arlington National Cemetery for a wreath-laying at the Tomb of the Unknown Soldier, joined by former Presidents Barack Obama, George W. Bush and Bill Clinton, along with their spouses.
The three former presidents recorded a free-flowing conversation at Arlington reflecting on the day's events and how to restore unity in a deeply fractured country.
Obama reflected on the graciousness that Bush and his wife, Laura, showed him and Michelle Obama during their inauguration in 2008, and said it was a reminder that "we can have fierce disagreements, and yet recognize each other's common humanity."
Clinton noted that the nation is struggling through a most unusual time, "trying to come back to normalcy, deal with totally abnormal challenges, and do what we do best -- which is try to make a more perfect union."
"I think the fact that three of us are standing here, talking about a peaceful transfer of power, speaks to the institutional integrity of our country," Bush said.
The former President notably missing from the conversation was Trump, and yet it was his absence that allowed the restoration of civility after so much rancor.
"I think if Americans would love their neighbor like they would like to be loved themselves, a lot of the division in our society would end," Bush said.