Sen. Hillary Rodham Clinton, D-N.Y., waves goodbye Saturday after addressing supporters at the National Building Museum in Washington, D.C., where she suspended her presidential campaign and endorsed Barack Obama.

Washington ? Hillary Rodham Clinton suspended her pioneering campaign for the presidency on Saturday and summoned supporters to use “our energy, our passion, our strength” to put Barack Obama in the White House.

“I endorse him and throw my full support behind him,” said the former first lady, delivering the strong affirmation that her one-time rival and other Democratic leaders hoped to hear after a bruising campaign.

Amid tears from her supporters, Clinton issued a call for unity that emphasized the cultural and political milestones that she and Obama, the first black to secure a presidential nomination, represent.

“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.

For Clinton and her backers, 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.

“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 in a speech before cheering supporters packed into the ornate National Building Museum, not far from the White House she longed to occupy again, as president this time.

Indeed, her speech repeatedly returned to the new threshold her candidacy had set for women. In primary after primary, her support among women was a solid bloc of her coalition. She noted that she had received the support of women born before women could even vote.

But her main goal was to heal the rift in the party – one that cleaved Democrats in part by class, by gender and by race.

“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.

Obama said he was “thrilled and honored” to have Clinton’s support.

Obama got the 2,118 delegates needed to clinch the nomination Tuesday. Aides said Obama watched Clinton’s speech live on the Internet. His campaign put a photo of the New York senator on its Web site and urged supporters to send her a message of thanks.