The United States presidential candidate Barack Obama will address Democrats at the party's national convention on Thursday, a day after being chosen as their candidate for the White House.
Mr Obama, the first African-American to be nominated for president by a major US party, will formally accept his historic candidacy in Denver, Colorado.
On Wednesday he was resoundingly endorsed by former President Bill Clinton.
Senator Obama will take the party reins with a speech that spells out his vision for change in America. He will deliver his address in Denver's open-air football stadium before 75,000 supporters on the 45th anniversary of Martin Luther King's "I Have a Dream" speech - a landmark in the US civil rights movement.
The televised speech will give the first-term Illinois senator his biggest national audience until he meets Republican rival John McCain in late September in the first of three face-to-face debates before the election on 4 November.
Senator Obama will speak from an elaborate stage backed by Greek columns, a grand setting some Democrats fear could distract from his economic message and feed Republican criticism that he is more political celebrity than man of the people.
National conventions are often the first time voters start to pay attention to a presidential race. Opinion polls show many voters are still unfamiliar with Obama and concerned about his readiness for the job.
Republicans, who hold their own convention in St. Paul, Minnesota, next week to nominate McCain, 71, hammered on their theme that Mr Obama is unprepared and his soaring speeches mask a lack of substance.
"The question for Obama is: 'What have you done and what have you run?'," Minnesota Governor Tim Pawlenty, a possible running mate for Mr McCain, said. "He has good oratory but when you shut off the teleprompter there's not much there," he said.