He set expectations high and now has to live up to them or risk a backlash.
When history landed, it was with car horns, tears, gunfire and echoes from historic corners of the city.
In a heavy drizzle shortly after midnight, several thousand people filled the barricaded segment of Pennsylvania Avenue between 15th and 17th streets in front of the White House dancing and chanting "O-ba-ma!" and "Whose house? Obama's house!" Some sang "America the Beautiful" and "The Star-Spangled Banner."
At 14th and U streets NW, hundreds of Sen. Barack Obama's supporters chanted, "Yes, we can!" People danced on bus shelters. Strangers hugged.
And Greg Rhett emerged from the Madison Hotel, pumping his fist as tears welled.
"Now the healing begins," said Rhett, 50, a consultant who lives in Ward 7. Now I can tell my 4-year-old you really can be whatever you want to be," he said. "We're going to get it right this time." Behind him, his wife, Candace, screamed at the top of her lungs:
Election night ended an extraordinary day in the Washington region, one charged with deep emotion and a vivid sense of history. Older African Americans wiped away tears as they cast their ballots, overwhelmed by the reality that in their lifetime a man of color was at the threshold of the presidency. Some went to the polls with icons linking them to loved ones: a poll-tax receipt, photos of long-dead relatives. Many brought their children to bear witness.
For Sen. John McCain's backers, the evening was subdued and sober. In a half-filled room at Westwood Country Club in Vienna, Republicans watched the returns with stoicism and perspective.
"What do I think? The sun will come up tomorrow," GOP volunteer Linda Schmidt said. "I hope there will be a level of coming together. It's a challenging time for all of us."
There was also bitterness. "What language do they speak in Kenya? Maybe I should get a book," said Ed Sellman of Falls Church. "I'd sure like to see his birth certificate."
"I guess there're not too many plumbers in Ohio after all," said Robert W. Farquhar of Burke. With McCain's prospects ebbing, Republicans in Fairfax County turned their hopes to keeping Democrats from winning a filibuster-proof majority of 60 seats in the Senate. "No 60 votes!" Del. David B. Albo said. "Then you know you're reaching low for a reason to party."
A few minutes after Fox News called the election for Obama, the bar was ordered to close and the big-screen TVs were turned off. "McCain should sue for all the votes stolen by ACORN," said Alex Sutono of Vienna. "I don't believe those numbers. It's not over. It's not over."
The most remarkable scene unfolded after midnight in front of the White House. Under the watchful eye of the Secret Service and the Park Police, a predominantly young crowd waved huge American flags and sported signs that said "Yes we did!" Some climbed fences around the construction site where inaugural reviewing stands are going up.
A group of about a half-dozen Georgetown athletes said they jogged spontaneously from campus after hearing of Obama's victory. "This might be the best day of my life," said Danielle Bailey, 18, a freshman from Florida.
Kyle Poole, 48, a financier, said he brought a flag because he felt "honored and proud."
"I was once a Republican," he said. "Then George Bush came to the White House and now I'm thrilled to be here with the flag."
As late as 2:30 a.m., revelers were streaming south on 16th Street by car and foot. In front of the darkened White House, chants of every stripe continued.
On a chain-link fence erected by inaugural construction crews, someone hung the sign: "Welcome Home Malia and Sasha!"
While many of those at the White House came from the celebration on U Street, others marched over from the 9:30 Club, where the hip-hop group Flobot halted its concert when Obama began speaking. Club patrons headed to the White House.
"It's the moment of change," said Ana Sarmiento, 19, of Colorado. "I've never seen anything like it."
In neighborhoods throughout the District, celebrations spilled onto the streets and filled the air. Police reported the sound of gunfire in four of the seven patrol districts but said there were no injuries.
Revelers turned U Street between 10th and 14th streets into a virtual Mardi Gras with music and dancing. "The good guys won!" shouted Jay Freni, 36, a waiter. "This is the moral arc of Martin Luther King. This is justice and people want it."
As firecrackers sounded close to 2 a.m., Bernard Gilchrest, stuck in traffic at 12th and U for more than an hour, was a happy man. The retired bus driver traded high-fives with total strangers while tooting on his horn.
"How many times in my life is this going to happen?" he asked. "God bless America. This has unified everybody."
At 3 a.m. Smiley Rouse was standing beside her silver VW convertible parked on U Street across from the African American Civil War Museum. The top was down, the music was cranked. The retired D.C. police officer had woken up 24 hours earlier, so wired about voting that she had time to rake the leaves in the front and side yards of her Northeast home before her mother called her to head out to the polls. "Obama 400 yrs" was scrawled in yellow marker on her windows.
After 400 years of slavery, she said, "We are alive to see a black man in a white house."
"I'm so glad to see the city come back after the '60's riots," said her mother, Vernell Garey, 57. "I'm proud of this city."
In the hours between the closing of the polls and the projection of Obama's victory, residents sat vigil in living rooms, bars, church basements and hotel ballrooms.
Clubs and cafes on U Street were jammed with revelers, erupting at each scrap of news about states awarded to Obama. At Busboys & Poets on 14th Street, where a racially mixed crowd stretched down the block, there wasn't a McCain supporter in sight.
"I never thought I would live to see this day," said Audrey Ross, 55, of Clinton.
The entire crowd at Reggiano's in Landover rose and applauded when CNN gave Ohio to Obama. "This is over. The rout is on," said Orland Johnson of Bowie, a member of Obama's national finance committee.
About 100 members of Union Temple Baptist Church in Anacostia began their CNN vigil with a prayer. Many cried and clapped, shouting "Hallelujah!" and "Thank you, Jesus!" when early returns showed Obama ahead. Valerie Morrison, 59, of Landover, Juanita Perry, 74, of Temple Hills and Mary Satcher, 71, of Southeast Washington call themselves the "Obama Mommas."
"This is the day Dr. King talked about," Satcher said. "I'm just glad I'm still here to witness it."
As the polls closed in the District, a small crowd of Democrats gathered in an anteroom at the Madison Hotel, where Denise Wright, an Advisory Neighborhood Commission member and a D.C. schools psychologist, grabbed the TV remote control, making the volume louder over the din. She seemed barely able to breathe watching while McCain showed early strength.
"Now it's okay to exhale a little," she said as Obama pulled ahead. "I will still stay up tonight until they declare him the president of the United States." In the main room, dozens cheered and screamed, "Yes, we can! Yes, we can!" as news of Obama's projected win in Pennsylvania was broadcast.
Grace Brune, 11, stood with her parents, Robert Brune and Janine Colmoletti, who decided to bring her to the Lincoln Memorial to capture the significance of the night.
"We were watching TV last night. Grace saw an Obama sign and said, 'Look -- it says, "Hope," ' and that's how we feel," Colmoletti said. Just then, someone shouted that Obama had won Pennsylvania. Colmoletti, holding a mini TV, looked at the screen and the states that had been counted.
Brune said: "I think the healing between races will leap forward tremendously. In psychology, they call it a paradigm shift."
The family stood near the marble columns waiting and watching the television for updates. Robert Brune looked out over the Reflecting Pool. "It stopped raining," he said. "The sky has parted for Obama."
In the Arlington County community of Nauck, founded in 1844 by former slaves, yesterday dawned as a day of wonder. The line to vote at Drew Model Elementary School started shortly after 3 a.m. and ran through the parking lot and into the street.
"There were some older folks waiting in line who'd never voted before in their lives," said John Lett, Nauck precinct captain for the Arlington Democratic Party.