Immigration rights activists said the size of their movement would be on display at rallies around the country, including in the nation's capital, where National Association for the Advancement of Colored People President Benjamin Jealous delivered the keynote address.
Gustavo Andrade, who leads a large immigrant advocacy group in Maryland and helped organize Wednesday's event, said about 400 buses carrying activists converged on Washington for the rally.
Several Democratic lawmakers including Sen. Bob Menendez and Rep. Luis Gutierrez, spoke briefly, as did Puerto Rican singer Olga Tanon and the Latino pop-rock group La Santa Cecilia.
The activists already claim victories nationwide, including a successful lobbying effort against a plan in North Carolina to provide driver's licenses to immigrants with the words: "NO LAWFUL STATUS."
The immigrant activism movement gained national attention in 2007 when President George W. Bush and a bipartisan group of lawmakers unsuccessfully tried comprehensive immigration overhaul. Some high school and college students who were brought to the U.S. as young children began living openly and holding rallies.
The movement gained new supporters in 2010, when Congress debated but did not pass the DREAM Act — legislation that would have granted legal status to young immigrants living illegally in the country.
President Barack Obama announced in June his deferred-deportation program allowing young immigrants to apply for work visas. During his State of Union address in February, Obama called on Congress to quickly pass sweeping immigration measures.
Associated Press writers Erica Werner in Washington, Claudia Torrens in New York, Elliot Spagat in San Diego, Terry Collins in San Francisco and Kate Brumback in Atlanta contributed to this report. Burke reported from San Francisco. Follow Luis Alonso Lugo and Garance Burke on Twitter at www.twitter.com/luisalonsolugo and www.twitter.com/garanceburke .