DENVER--Democrats formally named Barack Obama their presidential candidate Wednesday, putting their hopes of ending eight years of Republican control of the White House in the hands of a man who would be the United States' first black president.

On a motion by former rival Hillary Rodham Clinton, delegates at the Democratic National Convention approved the nomination by voice vote -- the culmination of a painstaking agreement worked out between the two camps to present a unified front.

Though the vote at the Democratic National Convention offered no surprises, its historical importance was undeniable. It capped the longest, closest U.S. primary race in memory as Obama, a political newcomer, defeated Clinton, the former first lady whose victory once seemed all but assured.

It also meant that Obama, the son of a black Kenyan father and a white American mother, is now one victory from becoming president of a nation where, just decades ago, many blacks were denied the vote.