CHICAGO — In the largest political protest here on any cause since the Vietnam War, tens of thousands of immigrant rights supporters demonstrated July 1 against the anti-immigrant “Minutemen” and in favor of the legalization of immigrants and the unification of immigrant families.

“The immigrants came out to show their faces, to show that they are real people with families and not terrorists,” Emma Lozano, president of Centro Sin Fronteras, an immigrant rights group, told the Chicago Sun-Times. “They are people with the same dreams as other people living in this country.”

The action followed an announcement that the racist, vigilante-like Minutemen organization, which has been stalking and terrorizing immigrants in border states such as California and Arizona, is establishing a chapter in the Chicago area.

Rafael Pulido, a disc jockey known as “El Pistolero” on a local Spanish-language radio station, made the initial call for the march to be held on the Chicago’s southwest side. His appeal captured the imagination of the city’s Mexican American and immigrant communities, and soon developed a life of its own. A rival disc jockey, Miguel Silva, known as “El Chokolate,” joined in the call for such a demonstration.

Major Latino and immigrant rights organizations, including Centro Sin Fronteras, Casa Aztlan, the Puerto Rican Cultural Center and the large number of organizations of “oriundos,” or people from specific towns or regions of Mexico or Latin America, started to mobilize, not only in Chicago but in the suburbs and surrounding cities as well. Many small businessmen in Mexican immigrant neighborhoods closed their businesses, allowing their employees to attend the Friday morning march.

Officials pledged cooperation. The Spanish-language print media in Chicago picked up the theme. The call was for everybody to wear white shirts to make clear who was participating in the demonstration.

Then came the morning of July 1. The turnout was immense: the Daily Southtown newspaper estimated the turnout at 40,000 and published a panoramic picture of the march lending credibility to this eye-popping figure.

The marchers’ demands were simple and straightforward, and wholly in line with those of the Immigrant Workers Freedom Ride and the entire immigrant rights movement: legalization, access to citizenship, family unity and an end to persecution. Speakers included Rep. Luis Gutierrez (D-Ill.) and other political and social leaders.

Though Pistolero and Chokolate did crucial work in promoting the mobilization, the efforts by labor and community groups had prepared the groundwork. And that political sophistication and readiness to act flowed from long years of organizing and struggle.

Marissa Graciosa from the Illinois Coalition for Immigrant and Refugee Rights told the World, “Change has got to happen.” She continued, “Immigrants are working hard, paying taxes, they feel they are part of the country.” Yet, she said, they are forced to live in the shadows. “People are sick of it. When they made a call for justice, people heard it and they came out.”