The  headline in today’s Denver Post, in World War III-sized type along with a gargantuan photograph of Hillary Clinton, said simply: THE TEAM PLAYER. That assessment was based on her speech Tuesday night, which may have been a tad too uncritical—but Senator Clinton certainly lived up to that headline today.

Earlier, Clinton had officially freed up her delegates to vote for Obama—and many did so. As the roll call vote for the Democratic presidential nomination went through its alphabetical list of states, Obama began piling up huge majorities. The 1,900 delegates that Clinton won in the primary season had shrunk to 341.5 when it was New York’s time to vote. Obama's tally stood at 1,549.5 votes. Democratic Party official Alice Germond called New York’s name. “New York, you have 282 delegates!” Then Clinton stole the show once again. She did more than free up her delegates. She did more than throw the weight of the huge New York delegation to Barack Obama. In an electric moment, she made a motion that the 2008 convention adopt Senator Barack Obama of Illinois as the party’s nominee “by acclamation.”

This gambit gave Clinton yet another moment in the spotlight even before her husband spoke to the convention—and he wowed them—and it induced roars of approval from the floor. House Speaker Nancy Pelosi, chairing the session and cued in ahead of time, played her part in the choreographed drama. Pelosi immediately called for a second to Mrs. Clinton’s motion, and thousands of delegates raised their hands and shouted their assent. Pelosi then called for the aye votes, and the roar was even louder. And then it was done.

The phrase “dancing in the aisles” is a cliché, but that’s what many Democrats did. Some cried, some laughed. Some laughed and cried. The Democratic Party, within the living memory of most of the delegates assembled in Denver, once clung to power on the bulwark of racial segregation. Today, it followed the lead of a female senator who ran a close second and unanimously named an African-American man as its nominee for president of the United States.

It was a watershed moment in American history, and those on the convention floor knew this—and knew also that they were privileged to be able to participate in it.