The rally was presented mostly an entertainment event, featuring stars like musician John Legend, singers Sheryl Crow and Kid Rock, hip hop band The Roots and actor Sam Waterston.
But the undertones were obviously political, with the state of the country's affairs foremost on people's minds.
Speaking at the National Press Club after the event, Colbert and Stewart said the event was not a political rally and was mostly done for entertainment.
"We're not running for anything," Stewart said. "We don't have a constituency. We do television shows for people that like them and we hope that they continue to like them so that Comedy Central can continue to sell beer to young people."
"We wanted to do a really good show for people that wanted it," he added.
The atmosphere in the crowd was one of comedic energy, with attendees carrying signs saying "Relax," "Freaking Out for Freedom," and "God Save Us from Ourselves."
Ginger Louerde, who traveled to the nation's capitol for the first time with her 10-year-old son, said she came to tell lawmakers and Americans to "stop shouting and play nice."
"I'm very concerned about what's happening on the right and about how they're pushing, pushing so hard against individual freedoms and I want to say, wait a minute, those of us on the left want to have a voice as well," Louerde, 42, told ABC News.
"You have to expect you're not going to hear that much at a rally this size," Barbara Young explained.
Young was the minority at the rally -- a veteran protestor who had experienced both the rallies of the 60's and today's events.
Samantha Desmarais, 23, said she drove from Rhode Island Friday night with her friends just to attend the rally.
"I hope to achieve sanity. We need sanity in the country. Things have gotten out of control. We need to fix things," said Desmarais, who wore a "Vote Sanity" sticker. "There's so much hatred and animosity ... and all this stuff is going on that does not need to happen. We need to come together as one and we need to reinstate our sanity, think positive, set some real goals and stop fighting each other."
Many attendees said they hoped the rally, taking place in the nation's capitol just days before the election, would ignite enthusiasm. In what has become a divisive election, Democrats face the prospect of losing control of the House and key Senate seats.
Crowds from around the country traveled to Washington to attend the event, similar to Beck's rally in August. The Huffington Post chartered 200 buses to bring 10,000 people to the event and several buses were reportedly still on their way even after the rally started. More than 220,000 people had RSVPed on the rally's Facebook page.
Carrie Halperin contributed to this report