Beyond the shadows of Chicago's impressive skyline, in the scarred urban landscape of the city's southside, the Regal Theater swelled with expectation and pride. In the area where Barack Obama worked as a community activist and his wife, Michelle, grew up, people had come to see their native son - their boy - fill a sports stadium in Denver a thousand miles away and hit it out of the park.
Some came dressed as though for church, complete with hats, slacks, earrings and handbags. Others came casual - sporting jeans and their candidate on their shirt. They came in all ages. Parents brought their children, who tried not to fall asleep. Grandparents brought each other and tried not to cry. But for the most part they came in one colour, black, and for one reason - history. They did not go home disappointed.
Alex Norwood left around 10pm jubilant, even if his children, aged four and six, were a little bleary. "It was the greatest," he said. "It was historic. I brought them so they could witness history."
In the video before the speech Obama recalled his grandfather taking him to see astronauts coming back to earth. As the boy sat on his shoulders his grandfather said: "We're Americans. We can do anything when we put our minds to it."
It was one of the many moments when the audience rose to their feet. But in this instance patriotism wasn't the half of what got them there. It was the unlikeliness of it. Watching Obama accepting the Democratic nomination at the Regal was like seeing a man return from the moon decades ago. The achievement had expanded the audience's understanding of what was possible. It compressed into an evening what they thought would never live to see in their lifetime. And it had left them incredulous.
Beatrice Sumlin grew up two blocks from 16th Street Baptist church in Birmingham, Alabama, where four girls at Sunday school were killed in a fire bomb attack by Klansmen just a few weeks after Martin Luther King's I have a dream speech. "I'm just blessed I could be here to see this day," she said. "Because I never thought I would see it. And now I've seen this, I've seen it all. My mother's still alive and she still can't believe it. This is history, honey."
The front page of the Chicago Sun-Times that morning showed a picture of a black delegate in Denver crying as Obama was nominated and the banner headline "Believe it". But the crowd at the Regal barely could.
"I've got to be honest with you, I never thought a black man would get this far," said Jimmy, who, in his sharp hat and silky shirt neither offered nor apparently required a second name. "But a lot of white people are hurting too right now. They're losing houses and jobs, so they're beginning to look past the colour thing."
The speech was well received. But then that was barely ever in doubt. As everyone knew what was going to happen, there was no suspense. But precisely because everyone knew what was going to happen there was plenty of anticipation. The evening had long been set up as a seminal occasion for America in general and black America in particular, on a scale usually reserved for sporting events. Like Joe Louis beating Max Schmeling in 1938 or Jackie Robinson in 1947 breaking baseball's colour bar and putting on a Brooklyn Dodgers' jersey for the first time, the very fact of it was a game-changer.
But that didn't make the game any less enjoyable to watch. Going to the cinema with large numbers of African-Americans is best described as part religious revival and part contact sport. The relationship between audience and image is active and interactive.
Like the call and response of a good Baptist sermon, the crowd's participation is neither demanded nor discouraged. People shout at the screen, yelling advice, caution and encouragement. "Go on now." "That's what I'm talking about." Or simply, "That's right."
Thursday night was no different By the time Obama took the microphone, there was no policy point or rhetorical flourish that did not find itself worthy of an amen and a cheer.
When he announced that he was accepting the nomination an ear-numbing thunder broke through the auditorium. They punched the air; some held each other. And many wept.
In the vestibule they sold Obamarabilia. Alongside the usual badges, hats, flags and placards, you could get your picture taken and superimposed on to a picture of him. There were T-shirts of him alone, and others with Martin Luther King and Nelson Mandela.
Addressing the convention on the 45th anniversary of King's I have a dream speech, the comparisons were inevitable. Indeed that was the point. King had called for freedom to ring from "the snowcapped Rockies of Colorado". For those at the Regal, Thursday represented the shift from the metaphor to the man. But for some the associations were also painful. "I believe he can win," said a barber a few blocks away earlier in the day. "I just hope he doesn't get killed. They've done it before."
Having disbelieved that he would get this far, the crowd were now prepared to believe anything - even that in two months' time America could have a black president. "With God anything is possible," said the woman taking names at the door. "I've got good vibes about this one," said the man selling T-shirts. "I know he's going to win," said Jimmy. How? "Because I believe."