Comedian Jon Stewart told hundreds of thousands of people gathered at the National Mall in Washington, D.C., that "we can have animus and not be enemies," as his three-hour laugh-fest with Stephen Colbert came to a serious conclusion.

Stewart's "Rally to Restore Sanity" and Colbert's "March to Keep Fear Alive" duelled it out, or joined forces, at what turned out to be part concert and part comedy show. It ended with a call on Americans to turn down the rhetoric from both ends of the political spectrum and work together.

In an impassioned 15-minute speech, Stewart told a crowd estimated to number at least 250,000, that their presence has restored his sanity.

"We live now in hard times, not end times. And we can have animus and not be enemies," Stewart said. "But unfortunately, one of our main tools in delineating the two broke. The country's 24-hour political pundit perpetual panic conflictinator did not cause our problems. But its existence makes solving them that much harder."

Stewart's speech was capped off with a short rendition of "America the Beautiful" by Tony Bennett before the show's many entertainers sent the crowd home with The Staple Singers' "I'll Take You There," led by Mavis Staples.

The boisterous crowd began gathering under sunny skies early Saturday morning, waving signs and wearing buttons that carried calming slogans like "Vote sanity," and "Relax."

After R&B group The Roots and singer John Legend, and the duo from Mythbusters, warmed up the crowd, Stewart and Colbert came out to push their messages of fear and sanity.

After Colbert emerged from his "Fear Bunker" in a narrow capsule like a rescued Chilean miner (Colbert briefly ran around the stage waving the Chilean flag, chanting "Chi-chi-chi, le-le-le"), the two brought out guests to get their messages across.

One of the biggest early surprises was when Stewart introduced Yusuf, formerly known as Cat Stevens, to sing his hit "Peace Train." Not long into his acoustic performance, Colbert brought Ozzy Osbourne to the stage to sing "Crazy Train." After the two artists battled back and forth, the comedians compromised with the O'Jays, who sang "Love Train."

The TV hosts and former colleagues on The Daily Show -- who have long played up their political enmity -- jointly applied for a permit for a rally for 25,000 people, but the crowd swelled well beyond that.

They were treated to musical performances by Sheryl Crow, Jeff Tweedy and Kid Rock, interspersed with video montages to garner laughs.

On a website designed to promote the event, Stewart said his Rally to Restore Sanity was for people who are generally too busy to go to rallies, and "who think shouting is annoying, counterproductive, and terrible for your throat; who feel that the loudest voices shouldn't be the only ones that get heard."

Stewart called on moderates, rather than political extremists whose commentary often polarizes the left and right, to show up.

"If we had to sum up the political view of our participants in a single sentence… we couldn't. That's sort of the point."

On his own similarly-designed website, Colbert satirically called on his fans to return to the principals he said America was founded upon.

"America, the Greatest Country God ever gave Man, was built on three bedrock principles: Freedom. Liberty. And Fear -- that someone might take our Freedom and Liberty," Colbert said before inviting people to pack an overnight bag and extra underwear for the march.

"Because, to Restore Truthiness we must always… Shh!!! What's that sound?! I think there's someone behind you! Run!"

Satellite rallies were also planned in cities such as Los Angeles, Chicago, Denver and Honolulu.

Jeffrey Juris, an assistant professor of anthropology at Northeastern University, said the rallies go beyond political comedy, and should be taken seriously.

"The point of the rallies, and The Daily Show and The Colbert Report more generally, is to use humor to shine a light on the contradictions, foibles and absurdities of our political culture in order to provoke critical reflection, particularly among young people who might not otherwise take an interest in politics," Juris wrote in an analysis piece posted on the university's website.

"In this case, the rallies go one step further and entail participatory action."

The rallies come a few weeks after conservative radio and television host Glenn Beck held a rally, also at the National Mall, on the 47th anniversary of Martin Luther King Jr.'s famous I have a Dream speech.