The tension mounted for days — and then broke, all at once.
CNN went first, calling the presidential election at 11:24 a.m. Eastern. It was followed in quick succession by NBC, CBS, ABC and The Associated Press. Fox News confirmed the outcome at 11:40 a.m., underscoring what its anchor Chris Wallace later called “the power of what we are seeing right now.”
“Here we have on Fox the headline, the chyron at the bottom of the screen, ‘Joe Biden Elected 46th President of the United States,’” Mr. Wallace told his viewers. “On Fox.”
The projection that Joseph R. Biden Jr. had beaten President Trump came after days of slow-burning suspense on the cable news networks and broadcast channels. As millions of anxious viewers watched, the anchors and pundits filled hours of airtime by tracking the vote counts in battleground states. All the while, President Trump fumed and filed legal challenges.
Some on-air personalities began to lose patience with the slow pace. On ABC on Friday night, Nate Silver, the editor in chief of FiveThirtyEight, was asked if he thought the race was over, and he replied, simply, “At this point, yeah.”
The anchor, George Stephanopoulos, and ABC’s supersized panel burst into laughter, with one panelist exclaiming, “Why are we still here then?”
Some viewers may have begun wondering the same, despite pre-election pledges by news outlets that they would be extra careful in tabulating results. But resolution came shortly before lunchtime on Saturday, courtesy of Wolf Blitzer on CNN.
“After four long tense days, we’ve reached a historic moment in this election,” Mr. Blitzer announced. “CNN projects Joseph R. Biden is elected the 46th president of the United States, winning the White House and denying President Trump a second term.”
It was a projection in Pennsylvania that tipped the networks’ models to a surefire Biden victory, as a batch of a few thousand ballots from Philadelphia trickled in, heavily skewed in Mr. Biden’s favor. “It is a cathartic moment for millions and millions of Americans,” said the CNN correspondent Abby Phillip.
Catharsis of a different sort came for the dozens of television producers, correspondents and anchors who had been overseeing a virtually 24-hour broadcast since Tuesday night, with some political analysts pulling overnight shifts in the event of a decisive development.
Rachel Maddow, MSNBC’s highest-rated anchor, had been the co-anchor of the network’s broadcasts all week until she had to go into isolation in what she called her “Covid quarantine cove” on Friday after a close contact tested positive for the virus.
On Saturday, Ms. Maddow appeared onscreen via Skype, explaining to viewers that she was cleaning her bedroom when she heard about Mr. Trump’s loss. (She said she was cleaning out the three-hole punch that she had used to make her research binder for election night and “Dustbusting up the little holes that fell out.”)
“I’m not sure this is the way I imagined I would learn that Donald Trump was a one-term president,” Ms. Maddow said. “But I’ll take it!”
Until Saturday, Fox News had appeared closest to calling the race for Mr. Biden because of its early call for the Democrat in Arizona, an election night projection that prompted criticism from Mr. Trump, and some rival data journalists, for possibly jumping the gun.
In the end, Fox News was the final TV network to project a Biden win. The anchor Neil Cavuto was holding down the 11 a.m. shift as other networks began to make the call; he informed viewers of those projections but said Fox News was not yet prepared to weigh in.
By 11:40 a.m., the network’s lead anchors Bret Baier and Martha MacCallum had arrived on the set. “The Fox News decision desk can now project that former Vice President Joe Biden will win Pennsylvania and Nevada, putting him over the 270 electoral votes he needs to become the 46th president of the United States,” Mr. Baier said.
Mr. Wallace told Fox News viewers that Mr. Trump “is going to end up with more votes than anybody in history — except for Joe Biden this year,” adding, “He is going to be a big player. He is not going to go away and be quiet.”
Still, Mr. Wallace seemed unimpressed with the president’s baseless talk of a fraudulent election and his legal challenges. “I think it’s going to become increasingly untenable,” he said, noting that Mr. Trump would need to find evidence of “industrial-strength election fraud and we have seen none of that so far.” He noted that Senator Lindsey Graham, Republican of South Carolina, had begun to talk of a Biden presidency and predicted that his Republican colleagues in the House and Senate would follow Mr. Graham’s lead.
Donna Brazile, a Fox News contributor who was formerly the interim chairwoman of the Democratic National Committee, wiped away tears as she reflected on the significance of Senator Kamala Harris becoming the first woman of color to be elected vice president.
“Been a long time coming, to be the last to get voting rights, to be those who waited and waited for our turn; it’s been a long time coming,” she said, after noting that she had been thinking about her grandmother, who did not have the right to vote. “This is not about asking anyone to leave the room. Just scoot over and let women also share in the leadership of this country.”
On CNN, the anchor Anderson Cooper asked the pundit Van Jones for his reaction. Mr. Jones, tearing up behind his eyeglasses, took a moment before saying, “Well, it’s easier to be a parent this morning. It’s easier to be a dad. It’s easier to tell your kids that character matters.”
The nail-biting week had exhausted anchors and audiences alike. On Friday, Jake Tapper of CNN acknowledged “frustration” among viewers, but evoked memories of the 2000 election, when networks had to reverse projections in Florida. “No one wants to go through that again,” he said, urging patience. “Everyone in the media wants to get it right.”
Shortly after Saturday’s projection, the major networks showed scenes of revelers celebrating Mr. Biden’s victory in American cities, as well as groups of Trump supporters in places like Harrisburg, Pa., who were waving Trump flags and carrying signs that said, “Stop the Steal,” a reference to the president’s unfounded claims that the election was fraudulent.
Mr. Trump, at that moment, was absent from the airwaves. He was off playing golf at a course in Virginia that bears his name.
Edmund Lee and Katie Robertson contributed reporting.