The vote was by acclamation after Senator Hillary Rodham Clinton waded onto the convention floor amid a standing ovation and stopped a roll call of delegations. She urged Obama’s unanimous selection as the party’s presidential nominee “in the spirit of unity, with the goal of victory”. Delegates shouted their affirmation, and the longest, most contentious Democratic primary fight in more than a generation came to a congenial halt.

Hours later, Bill Clinton did his part for party peace by wrapping Obama in his unqualified embrace. “Hillary told us in no uncertain terms that she’ll do everything she can to elect Barack Obama,” Clinton said, a day after his wife pledged her unstinting support. “That makes two of us.”

In a country with a difficult history of race relations, Obama overcame more than skin colour to achieve his triumph. As the son of a white mother from Kansas and a black father from Kenya, his background is hardly that of a typical presidential candidate. And his victory comes less than four years after he left the Illinois state Senate. A major goal this week is convincing voters that he has the experience to understand their lives and step into the White House.