Senator Hillary Rodham Clinton, D-NY, pauses as she speaks at the National Building Museum in Washington, yesterday, formally ending campaign to become the first woman president. - AP

WASHINGTON (AP):

Hillary Rodham Clinton ended her historic campaign for the presidency yesterday and told supporters to unite behind rival Barack Obama, closing out a race that was as gruelling as it was groundbreaking.

The former first lady, who as recently as Tuesday declared herself the strongest candidate, gave Obama an unqualified endorsement and pivoted from her role as determined foe to absolute ally.

"The way to continue our fight now to accomplish the goals for which we stand is to take our energy, our passion, our strength and do all we can to help elect Barack Obama the next president of the United States," she said in a speech before cheering supporters packed into the ornate National Building Museum, not far from the White House she longed to govern from.

Extraordinary campaign

"Today as I suspend my campaign, I congratulate him on the victory he has won and the extraordinary campaign he has won. I endorse him and throw my full support behind him and I ask of you to join me in working as hard for Barack Obama as you have for me," the New York senator said in her 28-minute address.

With that and 13 other mentions of his name, Clinton placed herself solidly behind her Senate colleague from Illinois, a political sensation and the first black to secure a major party presidential nomination.

For Clinton and her supporters, it was a poignant moment, the end of an extraordinary run that began with an air of inevitability and certain victory. About 18 million people voted for her; it was the closest a woman has come to capturing a nomination.

Great support

"Although we weren't able to shatter that highest, hardest glass ceiling this time, thanks to you, it has about 18 million cracks in it and the light is shining through like never before," she said.

Indeed, her speech repeatedly returned to the milestone her candidacy represented for women. She also acknowledged the unprecedented success of Obama's candidacy.

"Children today will grow up taking for granted that an African American or a woman can, yes, become the president of the United States," she said.

Obama secured the 2,118 delegates needed to clinch the nomination Tuesday after primaries in South Dakota and Montana. He planned to spend the weekend at home in Chicago.

Joining Clinton on stage were her husband, former President Bill Clinton, and their daughter, Chelsea, to loud cheers from the crowd. When she spoke, they stepped away.

Clinton supporters began lining up at dawn to attend the farewell address. A smattering of Obama backers showed up as well, saying they did so as a gesture of party unity.

Supporters and press jammed the museum's vast ground floor, with the second and third floor balconies quickly filling up as well. The stage was draped with American flags, and a sound system blared upbeat music.

As they awaited her arrival, campaign staffers milled the room, exchanging hugs and saying goodbye.