Even nature went out of its way to make it the perfect night for Barack Obama. On a warm, summery evening in usually frigid Chicago, people gathered in their hundreds of thousands for what they knew was the greatest victory party of their lives. They stood together in Grant Park, roaring as they watched the giant jumbo screens, belting out CNN, announce that key state after key state had fallen to Obama. They whooped when New Hampshire and Pennsylvania were declared for the Democrat - states that John McCain had to win - barely containing their joy. Couples embraced; one man began pogoing on the spot. But when they heard, shortly after 8.30pm local time, that Ohio had fallen into the Obama column, they at last put aside their superstition and their angst, and allowed themselves to believe that the prize was theirs. They knew that no Republican had won the presidency without Ohio in nearly 50 years. It was Ohio that had broken Democratic hearts four years ago. Yet Obama had won it - and won it big. This is what the crowds in Grant Park had come for: to see history made before their eyes, to witness an epochal moment in the great American story. "I am 63 years old, I marched with Dr King in Selma, Alabama and I never thought this day would come," said Linda Slaughter, her face shining with joy. Now, at long last, four decades after the bloody battles for civil rights, she believed that any American could fulfil their potential, regardless of their race. "The day has come when anybody in America can be who they want to be." Just imagining a black man as president was thrilling. "I think he'll be the smartest, greatest president we've ever had," she said, all but brimming over. The delight was shared by fathers and sons wearing unofficial souvenir T-shirts declaring "President Obama, commander in chief". The Obama camp had been wary of making a premature declaration. Even as the chances of a McCain victory grew more distant, his path through the electoral college more unlikely, they were counselling caution. Earlier, they had reacted to a set of exit polls that predicted an earth-moving landslide with a declaration that they simply didn't believe them. Too many of them remembered the afternoon exit polls of 2004 - which anointed John Kerry as president. But like an Elizabethan play, in which the elements foretell the affairs of kings, the weather in Chicago seemed just one of several signs that a new, sunnier era was on the way. In the lead-up to election day, Obama had been addressing crowds numbering in the tens of thousands. His final campaign rally had brought 100,000 people to Manassas, Virginia, close to midnight. McCain, meanwhile, had struggled to draw more than a couple of thousand supporters. In the Britain of April 1997, it was clear - palpable in the air - that the country was hungry for change. It was hard not to sense that same mood in America this autumn. You could feel it at the polling station for the 42nd ward of downtown Chicago. There, inside a building that houses both a student hall of residence and a retirement home, a steady line of old and young had streamed in to pick up their ballot papers and fill in the solid black line that marked a vote for Obama for president. "It feels like a new era kind of dawning," said Peter Morris, a 23-year-old theology student. He had recently visited relatives in Oklahoma and their racism had shocked him: "There was an attitude, even among some Democrats, that they wouldn't vote for him because he's black." Morris had voted with enthusiasm, he said, partly to show those relatives they were wrong. He had been able to zip in and zip out. But for 66-year old Louise Buchanan, it was a longer journey. Using a walking frame, she inched towards a polling booth, stopping to catch her breath. Once there, she took her time, reading each line on the lengthy ballot. Eventually the job was done. She handed her paper to one of the young volunteers who fed it into the electronic scanner - and a smile spread across her face. "I didn't think I would live to see this," she said afterwards. "So many from our past didn't live to see this." She had grown up in the deep southern state of Mississippi. "I didn't get to go to school when I was coming up." She had worked instead, picking cotton. And now she was voting for the man she hoped would become America's first African-American president. "I feel like it's gonna be better for people of colour." Hours earlier, a little after 7.30am, the Obamas had cast their votes, their daughters in tow, at their polling station in the ultra-liberal, arugula-and-latte neighbourhood of Hyde Park. They narrowly avoided what could have been an awkward, and even politically costly, collision. An earlier visitor to the same polling station was the Obamas' neighbour, William Ayers, the former leader of the Weather Underground involved in a string of bombings in the 1960s. Obama's connection with Ayers had formed a large plank of the Republican case against him - and the two men missed each other at the Beulah Shoesmith elementary school by just a few minutes. While Obama filled in his ballot form, his seven-year-old daughter, Sasha, could be seen clutching his leg, a picture of childish impatience. His wife Michelle had her head down, concentrating hard on that lengthy ballot paper. Afterwards Obama joked with reporters: "I noticed that Michelle took a long time," he said. "I had to check to see who she was voting for." Obama was asked if he was feeling sentimental. He was on the brink of winning the presidency, barely more than 24 hours after the death of the woman who had raised him, his grandmother Madelyn Dunham. "You know I'm sure I will tonight," he said. For now, though, "I feel really good.