More than 100,000 people marched to the state Capitol Monday afternoon, capping a hours-long rally to support federal legislation that would allow many of the 11 to 12 million undocumented immigrants in the country become U.S. citizens.

The crowd, most of them wearing white T-shirts to symbolize their peaceful intentions and carrying U.S. flags, marched 2¼ miles from the Arizona State Fairgrounds to Wesley Bolin Plaza next to the state Senate and House buildings. Their intent: to keep pressure on the U.S. Congress to come up with immigration reform that allows for legalization, rather than punitive treatment, of those who have come into the United States illegally.

At the Capitol, a series of speakers that ranged from U.S. Reps. Raul Grijalva and Ed Pastor - the two lone Democrats among Arizona's congressional delegation - to recent immigrants, leaders of the Hispanic community and clergy people spoke of the historic assembly, one of the largest in Valley history. They told the crowd that they must build on the momentum to further the cause of Hispanics.

One speaker, identified as Tomas Chavez, said he's an immigrant from Mexico who proudly served for two years as a U.S. combat medic in Iraq for his "new country."

He urged the crowd to not be complacent, to vote or be otherwise politically active. "Don't let this just be a day of marching," Chavez said.

Two conservative Republican state lawmakers walked around the Capitol amid the throng of marchers with their own homemade signs. Glendale Rep. Jerry Weiers' sign read: "Border security isn't racism. It's smart." Just a few feet away, Rep. John Allen, who was approched by several demonstrators throughout the day, held a two-sided sign: "Washington: No amnesty. Enforce the law. Close the border." The other side read, "Governor, I will hold them off, you get the National Guard."

Allen, a Scottsdale Republican, told some of the marchers: "We have to close the border. Let's close it first and then talk about everything after that."

One in the crowd, Frank Little, challenged Allen. "Why aren't you picketing businesses?" To that Allen said, "We should be making sure businesses aren't hiring illegals. I agree with you. In fact, we probably agree on a lot of things."

The crowd began to disperse a little after 4 p.m., after a rally that began in earnest around 10 a.m. at the fairgrounds, where they first gathered. The throngs created havoc for traffic in the central and downtown Phoenix area; most of the smattering of businesses along the Grand Avenue portion of the march chose not to open Monday.

"I saw the parade up close and now I've seen it in the air, and I've never seen anything like it," Phoenix Mayor Phil Gordon said.

Gordon stood at the corner of Fourth Avenue and Washington Street as the first wave of marchers turned on to Washington. The crowd erupted into cheers the mayor made his way to the front of the procession and shook hands with the leaders of the march.

Many in the crowd carried banners of the march's theme: Somos America: Hoy Marchamos Mañana Votamos, meaning We are America: Today We March, Tomorrow We Vote.

A good number of them were undocumented immigrants, among them 20-year-old Martin Rios, who came from Mexico seven months ago.

"In my country I had no opportunities, that's why I'm here. That's why many of us are here,'' said Rios, holding a big American flag. "We're here to work and we work hard, which benefits all of us. We're an important part of America."

At least 120 cities from Los Angeles to New York are participating in the National Day of Action, which include student walkouts, rallies, demonstrations and candle light vigils.

The waving of U.S. flags is a marked difference from an earlier march last month in which some walked with Mexican flags, drawing criticism that the expression was unpatriotic and anti-American.

Groups of men and women chanted. "Viva Mexico" and "necesitamos papeles" or "we need immigration papers.""We're doing this for our rights, we need respect,'' said Mexican native Maria Concha Rodriguez as she stopped on the corner of Grand Avenue and Roosevelt. She now lives in North Phoenix and said she's undocumented. "We're not criminals. Together we get more attention."

Although the vast majority of the crowd was Latino, including undocumented immigants, legal residents, there were also some non Latino supporters.

Heather Fisher, 39, of Chandler, said she took her took two children, Grant, 10, Ryan, 9, out of school so they could experience the historic moment and to get a feeling of what its like to be a minority. She supports undocumented immigrants to acheive legal status. "We need them as much as they need us," Fisher said.

Phoenix resident Shane Lee, 30, who operates his own landscaping business and estimates that more than half his workers are undocumented, showed up at the rally to honor a group that he called some of the hardest working employees he ever had.

“That’s the thing. They are such great workers that you can’t help felt a little angry over bills that want to criminalize them,” Lee said. “Illegal or not they’ve earned the right to be here.’’

Two Mesa residents advocating for stricter immigration reform attended Monday’s rally, holding “No amnesty” and close the border now’’ signs.

“We have no problem with immigration as long as is legal, so we thought we exercise our rights as Americans to protest,” said Steve Campbell, 47-year-old retiree. The two stood behind a line of 6 Phoenix police officers that separated them from the streams of demonstrators walking down 3rd Ave., toward the state Capitol.

Some of the marchers booed at them while other kissed the American flag to stress a point. “So far everyone has been pretty much respectful so I’m glad we came,’’ said Campbell.

The demonstration, in support of comprehensive immigration reform, passed near buildings where thousands of state employees work, as well as city, municipal and federal court buildings, but away from the heart of downtown.

Lopez and her employees handed out bottled water and passed nutrition bars from a truck parked inside her garage.

"They are my people, so I decided to show support by handing this out,'' Lopez said. "It doesn't matter that we're closed for business. This is more important.''

Monday's march comes just two weeks after a March 24 protest drew 20,000 supporters and paralyzed 24th Street and parts of the city's east side, surprising organizers and catching city officials off guard. That march was to protest a bill passed by the House in December that would have reclassified undocumented immigrants as felons, and made people who assist them vulnerable to prosecution.

The national demonstrations, which began early last month in Chicago with at least 100,000 people, have galvanized hundreds of thousands of immigrant and U.S.-born Latinos to a level not seen since the Chicano Movement of the 1960s and 1970s, when Hispanics protested political and educational systems they believed to be unjust.

Voter registration groups in Phoenix and other cities hope to leverage that enthusiasm by signing up new voters, and encouraging eligible immigrants to become citizens.

Latinos historically have had low turnout during elections, and immigrants from Mexico have typically lagged behind other immigrant groups in becoming citizens, further diminishing their political clout. Nineteen percent of the nation's 40 million Latinos voted in the 2004 Presidential election, according to data compiled from the U.S. Census by the Thomas Rivera Policy Institute, a research center based at the University of Southern California.

Of the 40 million Latinos in the U.S., 16 million are U.S. citizens, but nearly 6.8 million of them were not registered to vote in 2004. Another 1.7 million registered voters did not cast ballots, according to the institute.