NEW YORK — They gathered on the quiet streets of Garden City, Kan., and in the chaos of downtown Manhattan. They rallied outside congressional offices and against the backdrop of the Statue of Liberty. They invoked names such as the Rev. Martin Luther King Jr. and Cesar Chavez.

Hundreds of thousands of people demanding U.S. citizenship for illegal immigrants spilled into the streets Monday in dozens of cities from New York to San Diego in some of the most widespread demonstrations since mass protests began around the country last month.

"American culture doesn't exist without immigrants," said Christine Salinas, a Peruvian-American high school sophomore in New York. "It's completely unfair, and I think it's about time we protest."

Rallies took place in communities of all sizes, from a gathering of at least 50,000 people in Atlanta to one involving 3,000 people in the farming town of Garden City, Kan., which has fewer than 30,000 residents.

Demonstrators in New York City held signs with slogans such as "We Are America," "Immigrant Values are Family Values" and "Legalize Don't Criminalize." One sign said: "Bush Step Down."

"We love this country. This country gives to us everything," said Florentino Cruz, 32, an illegal worker from Mexico who has been in the United States since 1992. "This country was made by immigrants."

The protesters have been urging lawmakers to help an estimated 11 million illegal immigrants settle legally in the United States. A bill passed by the House would crack down on illegal immigrants and strengthen the nation's border with Mexico. A broader overhaul of immigration law stalled in the Senate last week.

Monday's demonstrations followed a weekend of rallies in 10 states that drew up to 500,000 people in Dallas and tens of thousands elsewhere. Dozens of other rallies, many organized by Spanish-language radio DJ's, have been held nationwide over the past two weeks, including one with more than 500,000 people in Los Angeles.

In the nation's capital, thousands of immigrants, their families and supporters marched Monday from Hispanic neighborhoods past the White House, then converged on the National Mall.

In North Carolina and Dallas, immigrant groups called for an economic boycott to show their financial impact. In Pittsburgh and other cities, protesters gathered outside lawmakers' offices. At the Mississippi Capitol, they sang "We Shall Overcome" in Spanish.

In Atlanta, many in white T-shirts, waving American flags, joined a two-mile march from a largely immigrant neighborhood.

The Rev. James Orange from the Georgia Coalition for the People's Agenda compared the march to civil rights demonstrations led by the Rev. Martin Luther King Jr. and farm-labor organizer Cesar Chavez.