US unions gave a high-profile boost to the long running protest against Wall Street and economic inequality, with members joining thousands of protesters in a Manhattan march.
Across the United States, students at several colleges walked out of classes in solidarity.
Sterling W Roberson, vice president for the United Federation of Teachers, said union members shared the same ideals as activists who have been camped out in sleeping bags.
"The middle class is taking the burden, but the wealthiest of our state and country are not," he said.
The Occupy Wall Street protests started on 17 September with a few dozen demonstrators who tried to pitch tents in front of the New York Stock Exchange.
Since then, hundreds have set up camp in Zuccotti Park and have become increasingly organised, lining up medical aid and legal help and printing their own newspaper, the Occupied Wall Street Journal.
Other groups have gathered and protested in cities throughout the US.
The protesters have varied causes but reserve most of their criticism for Wall Street, saying "we are the 99%" - in contrast to the wealthiest 1% of Americans.
Thousands packed Foley Square, an area encircled by courthouses, and marched to the protesters' unofficial headquarters nearby.
People in the crowd were carrying red-white-and-blue signs bearing a giant, star-graced A - representing the motto "Rebuild America." Other signs carried slogans saying "Tax Wall Street" and "Make Jobs Not Cuts."
One of the larger protests outside New York City today was in Boston, where about 200 Northeastern University students gathered on campus to condemn what they called corporate control of government and the spiralling costs of their education.
Hundreds of college students at New York's sprawling public university system walked out of classes Wednesday afternoon.
"The state of education in our country is ridiculous," said student Danielle Kingsbury, who said some of her professors had increasing workloads because of budget cuts.
"The state doesn't care about it, and we need to fight back about that."
The New York protests drew international attention on Saturday when about 700 members of the Wall Street group were arrested and given disorderly conduct summonses for spilling into the roadway of the Brooklyn Bridge on Saturday despite warnings from police.
