Barack Obama is the Democratic Party’s presidential nominee today and pledged to “bring a new and better day to America”.
The 46-year-old Illinois senator will make history as the first black presidential nominee of a major US party after he clinched victory on the final day of one of the closest and most expensive primary seasons in memory.
Mr Obama will now face Republican John McCain in November’s general election to decide who will be the 44th president of the United States.
He came under immediate pressure to consider rival Hillary Clinton as his running mate after she gave a speech in which she appeared to wield her power and influence, rather than concede defeat or suspend her campaign.
But Mr Obama simply praised his rival and dedicated his victory to his grandmother Sarah Obama in Hawaii whom he said “helped make me the man I am today”.
“Tonight is for her,” he said.
Speaking to thousands of supporters in St Paul, Minnesota, Mr Obama paid tribute to Mrs Clinton and said she had made him a “better candidate”.
The junior senator, who was virtually unknown across America four years ago, told a crowd of around 20,000 cheering supporters: “Senator Hillary Clinton has made history in this campaign, not just because she is a woman who has done what no woman has done before, but because she is a leader who has inspired millions of Americans with her strength, her courage and her commitment to the causes that brought us here.”
He congratulated Mrs Clinton on her campaign and also praised former president Bill Clinton’s economic policies.
Mr Obama acknowledged he and Mrs Clinton “certainly had our differences this past 18 months” but praised her desire to improve the lives of ordinary Americans.
“And you can rest assured that when we finally win the battle for universal healthcare in this country, and we will win that fight, she will be central to that victory,” Mr Obama said.
“Our party and our country are better off because of her and I am a better candidate for having had the honour to compete with Hillary Rodham Clinton.”
Mr Obama went on: “After 54 hard-fought contests our primary season has finally come to an end.
“We mark the end of one historic journey with the beginning of another, a journey that will bring a new and better day to America.
“Because of you... I can stand here and say that I will be the Democratic nominee for president of the United States of America.”
Turning to the general election campaign with his message of hope and change, Mr Obama said: “Let us begin the work together. Let us unite in common effort to chart a new course for America.”
He went on: “America, this is our moment. This is our time. Our turn to turn the page on the policies of the past.”
Speaking at the site where the Republicans will hold their national convention in September, Mr Obama focused on Republican John McCain, a former Vietnam prisoner of war who had criticised him in a speech earlier in the evening.
“In just a few short months, the Republican Party will arrive in St Paul with a very different agenda,” he said.
“They will come here to nominate John McCain, a man who has served this country heroically.
“My differences with him are not personal; they are with the policies he has proposed in this campaign.”
He challenged Mr McCain’s claims of independence, and added he voted with President George Bush 95% of the time last year.
“There are many words to describe John McCain’s attempt to pass off his embrace of George Bush’s policies as bipartisan and new,” Mr Obama said.
“But change is not one of them.”
Mr Obama clinched the nomination on a day in which the two Democratic rivals split the last two primaries, with Mrs Clinton winning South Dakota and Mr Obama taking Montana.
Mrs Clinton showed no sign of suspending her presidential campaign in a speech which was widely seen as the former first lady flexing her power and influence.
She even urged her “18 million” supporters to visit her campaign website and share their views on what she should do next as she said she would be “making no decisions” last night.
But she did say that the Democratic Party was “stronger and more vibrant” as a result of Mr Obama’s campaign.
Speaking at Baruch College in her home city of New York, Mrs Clinton said her rival had “inspired so many Americans to care about politics”.
She told cheering supporters: “Now the question is, ’Where do we go from here?’ And given how far we’ve come, and where we need to go as a party, it’s a question I don’t take lightly.
“This has been a long campaign and I will be making no decisions tonight.”
Earlier, she said: “I understand that a lot of people are asking, ’What does Hillary want?’
“Well, I want what I have always fought for in this whole campaign.”
She said she wanted to end the war in Iraq, wanted to turn the troubled US economy around and wanted universal healthcare in America.
She said she also wanted those who voted for her “to be respected, to be heard”.
The tone and content of her speech was seen by some political pundits as a final refusal by Mrs Clinton to leave the stage.
Earlier, speaking to a much smaller, less-animated crowd of supporters in New Orleans, Louisiana, Mr McCain said Mr Obama would be a “formidable” opponent but criticised him for offering “the wrong change” which “looks not to the future but to the past for solutions that have failed us before and will surely fail us again”.
But his speech was noted more for the stark visual contrast it presented when compared with the much bigger, livelier rally held by Mr Obama than for his criticism of the Democratic Party’s presumptive nominee.