Denver, Colorado - John Lewis, a black congressman who shared the podium when Martin Luther King Jr delivered his famous I Have A Dream speech, called Thursday for Democrats to "march on the ballot box" to elect the country's first African-American president.

Lewis spoke at Denver's Denver's Invesco Field on the 45th anniversary of the event, just hours before Senator Barack Obama, 47, was to accept the Democratic Party's presidential nomination.

Obama is the first black presidential nominee of a major party in the United States.

"With the nomination of Senator Barack Obama ... we are making a down payment on the fulfillment of that dream," Lewis told the crowd assembled on the football field in the late afternoon sun.

By the time of Obama's speech at 8 pm (0200 GMT Friday), the crowd was expected to swell to 75,000.

King's daughter, the Reverend Bernice King, said that the audience would be witness to what has become of her father's dream: "the acceptance of a Democratic presidential nominee decided not by the color of his skin but by the content of his character."

Obama's nomination marks a changing of the guard from ageing civil-rights leaders who faced death and jail to see black Americans treated equally in US society and institutions.

As segregation laws were repealed and equal opportunities opened up, younger African-Americans have broken down one barrier after another in the recent era.

Lewis noted that he is the last surviving speaker from the 1963 event, which drew 250,000 people to Washington and etched the civil rights movement into the nation's conscience.

"For those of us who stood on the steps of the Lincoln Memorial, or who in the years that followed may have lost hope, this moment is a testament to the power of the vision of Martin Luther King Jr," Lewis said. "It is a testament to the promise of America."

As a backdrop to Obama's speech, the stage is set with Greek columns that resemble the Lincoln Memorial on Washington's mall. But French doors make the podium background look like a famous portico at the White House.

King's son, Martin Luther King III, warned that realizing his father's dream was "not Barack Obama's job alone. American needs more than a great president to realize my father's dream. What America needs is a great America." (dpa)

Denver, Colorado - Democratic presidential hopeful Barack Obama is vowing to end US dependence on Middle East oil within 10 years if elected president, according to excerpts released ahead of his speech to the Democratic Party Thursday in Denver.

"For the sake of our economy, our security, and the future of our planet, I will set a clear goal as president: in 10 years, we will finally end our dependence on oil from the Middle East," Obama said.

Obama was nominated Wednesday night by the Democratic Party and is to accept the nod before a throng of 75,000 people at Denver's Invesco Field.

It's not the first time that Obama has made the pledge about oil dependence, but it is prominent within a speech that sets his goals as president.

Obama took aim at his presumptive Republican rival John McCain, charging that the Arizona senator had been in Congress for 26 of the 30 years that Washington has been talking about "our oil addiction."

"In that time, he's said no to higher fuel-efficiency standards for cars, no to investments in renewable energy, no to renewable fuels," Obama said. "And today, we import triple the amount of oil as the day that Senator McCain took office."

Obama is also to note that more US workers are jobless or "working harder for less," and more have lost their homes and are falling behind on their credit-card bills and university tuition payments.

"America, we are better than these last eight years. We are a better country than this," Obama was to say. (dpa)