The Illinois Coalition for Immigrant and Refugee Rights conducted the workshop for more than 100 immigrants.
Gov. Pat Quinn helped a permanent resident fill out her citizenship application.
He also spoke at the event, which was called "One Nation, One Dream."
"The highest office in a democracy is not the office of president or governor or mayor. It's the office of citizen," Quinn said.
The West Side Technical Institute of Daley College was designated a U.S. courtroom for Saturday so that a federal judge could give the oath of citizenship to 26 applicants.
Then the judge and the governor greeted and congratulated each of the new Americans.