Beck was joined at the rally by, among others, Sarah Palin, who was Senator John McCain's vice presidential running mate in their failed White House campaign against Barack Obama two years ago.
Neither Beck nor Palin made overtly political comments.
Palin likened the rally participants to the civil rights activists who came to the National Mall to hear King's historic speech.
She said the same spirit that helped civil rights activists overcome oppression, discrimination and violence would help this group as well.
"We are worried about what we face. Sometimes, our challenges seem insurmountable. Look around you. You're not alone," Palin said.
Beck is known for his extreme views and statements, including describing Obama, the first black US president, as a racist.
At the rally he repeatedly spoke about religion, urging participants to rely on faith to help the US recover from an economic recession.
"America today begins to turn back to God. For too long, this country has wandered in darkness,'' Beck said.
"Faith is in short supply. To restore America, we must restore ourselves.''
Nick Spicer, Al Jazeera's correspondent at the rally, said that while there were no politics on the podium there were plenty in the public arena.
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"[People here] say that their real motivation is fighting against big government and government spending, stopping the upcoming tax increases and slowing down the progressive politics that they see coming out of Washington," he said.
"But there have been controversies about the relatively low representation of African Americans and Latinos [in this movement]."
Dianna Reimer, of the Tea Party Patriots from Philadelphia, told Al Jazeera that the rally was about "restoring honour to our military, to America and our founding fathers".
"There is a lot lacking in respect for America today, it is a lot different to when I grew up," she said.
"Different ethnic groups that come to the US don't understand the founding principles the US was built on.
"Martin Luther King was an American. We are all people and we are all Americans. I don't think anyone has a monopoly on anyone."
Critics of the movement are in an uproar. The rally has dominated evening talk
programmes on the MSNBC cable television network and radio stations.
Reverend Al Sharpton, leading a march to the site of a planned King memorial, criticised the nearby Beck rally.
"The folks who used to criticise us for marching are trying to have a march themselves,'' he said.
"We come because the dream has not been achieved. We've made a lot of progress. But we still have a long way to go."
He said he was not seeking a confrontation with those at the Beck rally.
"We wouldn't disgrace ourselves today by allowing you to provoke us,'' he said in remarks directed at the Beck followers.
In an opinion piece for the Washington Post, King's son drew a contrast between Beck's right to call a rally and the political and racial beliefs of those expected to attend.
"My father championed free speech. He would be the first to say that those participating in Beck's rally have the right to express their views,'' King wrote.
"But his dream rejected hateful rhetoric and all forms of bigotry or discrimination, whether directed at race, faith, nationality, sexual orientation or political beliefs."
Beck's rally is the latest symptom of rampant political partisanship that is splitting the country two months before nationwide Congressional elections, which could cost Obama's Democrats their majority in the House of Representatives and perhaps the Senate as well.