US Democratic presidential candidate Barack Obama has told a cheering crowd of thousands of supporters that he will be the party's nominee for president.
The 46-year-old first term senator from Illinois spoke in Minnesota -- in the same convention center where John McCain is to receive the Republican nomination in September.
He said his Democratic rival, Senator Hillary Clinton, made history for doing what no woman has done before, calling her a leader who has inspired millions.
Obama, who will be the first African-American to become a nominee for a major political party, said the campaign marks the end of one historic journey with the beginning of another.
Obama secured enough delegate votes Tuesday, as the states of Montana and South Dakota held the last of the nominating contests.
He is set for a showdown against the 71-year-old McCain, a veteran Republican lawmaker from Arizona, in the November general election. The two have already taken verbal swipes at each other -- Obama during the event in Minneapolis and McCain during an evening rally just outside New Orleans.
Clinton addressed thousands of cheering supporters in New York City. She recognized Obama for what she said was his extraordinary campaign that inspired and empowered Americans. But she said she will not make a decision right now on what her next political step will be.
The support of superdelegates helped moved Obama towards the necessary two-thousand-118 delegates needed to clinch the nomination.
Sources close to the former first lady say she would consider joining Obama as his running mate if it would help Democrats win the White House in the November election.
Earlier Tuesday, Obama won the support of a key superdelegate -- South Carolina Congressman James Clyburn, the third-highest ranking House Democrat. Former U.S. President Jimmy Carter is also expected to endorse Obama.
Superdelegates are elected officeholders and party activists who are free to vote for any candidate at the nominating convention this August in Denver, Colorado.