DENVER (AP) _ Barack Obama will accept the Democratic Presidential nomination Thursday night at an open-air rally that's expected to draw up to 75,000 people.

He's already made history as the first black American to head a major party ticket. He made a surprise appearance in the convention Wednesday night to thunderous applause.

Barack Obama was nominated by acclamation Wednesday, with his former rival Hillary Clinton interrupting the roll call in what she called ``the spirit of unity, with the goal of victory.''

Later Bill Clinton delivered a ringing endorsement of Obama, saying Obama is ``ready to lead America and restore American leadership in the world.''

In his Vice Presidential acceptance speech, Joe Biden told delegates that the nation requires ``more than a good soldier'' in The White House. He said Barack Obama is a wise leader who can deliver the change the nation needs.