Hillary Clinton ended her presidential bid and endorsed Barack Obama this evening, urging her supporters to unite behind his candidacy and help recapture the White House for Democrats in November.
In the first step toward healing the wounds of a sometimes bitter five-month Democratic nominating battle, Ms Clinton told a cheering crowd at her final rally that she would work hard to put Mr Obama in the White House.
She urged her supporters to unite behind the Illinois senator in his general election race against Republican John McCain.
"I will work my heart out to make sure that Senator Obama is our next president," Ms Clinton told a crowd of about 2,000 at the National Building Museum in Washington. "I ask all of you to join me in working as hard for Barack Obama as you have for me."
With her husband, former President Bill Clinton, and her daughter, Chelsea, standing to the side of the stage, Ms Clinton said she and Mr Obama shared the same values and goals.
"I endorse him and I throw my full support behind him," she said. "We will make history together."
Ms Clinton, a New York senator and former first lady, was once the heavy favorite to become the first female US president. She had resisted calls to pull out of the race for months as the split between their supporters grew wider.
Her mention of Mr Obama's name drew "boos" from some in the crowd, but she said it was time to put aside their differences and concentrate on winning in November.
"This has been a tough fight, but the Democratic Party is a family, and now it's time to restore the ties that bind us together and to come together," she said.
Mr Obama did not appear at the rally, giving Ms Clinton the spotlight for the day. Ms Clinton won more than 17 million votes during the Democratic nominating battle, and Mr Obama has tried to build bridges to her camp ahead of the November campaign.
He said in a statement he was "thrilled and honored" to have Ms Clinton's support and praised her campaign for shattering barriers for women and inspiring Democratic voters.
"Our party and our country are stronger because of the work she has done throughout her life, and I'm a better candidate for having had the privilege of competing with her," Mr Obama said.
Ms Clinton's decision to suspend her campaign rather than formally disband it means she retains some control of her delegates and can still work to repay more than $20 million in campaign debt, including more than $11 million she loaned the campaign from her own pocket.
She was generous in her praise for her former rival, who will be the first black presidential nominee of a major US political party.
"I've had a front row seat to his candidacy and I have seen his strength and determination, his grace and his grit," Ms Clinton said.
"When I started this race, I intended to win back the White House and make sure we have a president who puts our country back on the path to peace, prosperity and progress," she said.
"And that's exactly what we are going to do by ensuring that Barack Obama walks through the doors of the Oval Office on January 20, 2009."
The appearance in Washington came two days after she and Mr Obama met privately, and follows weeks of speculation about the likelihood she will become Mr Obama's running mate.
Ms Clinton made no mention of that possibility during her speech. She has said she is open to the idea, a prospect that excites many supporters, but is viewed with skepticism in Mr Obama's camp.
Some of her supporters have tried to pressure Mr Obama into picking her, but her campaign issued a statement on Thursday saying she is not seeking the vice presidential slot.
Ms Clinton entered the race in January 2007 as the clear front-runner and was viewed as the almost certain winner for most of the year, but stumbled to a third-place finish behind Mr Obama in the first contest in January in Iowa.
She bounced back five days later to win in New Hampshire, but never recovered from Mr Obama's string of 10 consecutive victories in February.