"Notwithstanding the economic climate, we the people, we the grassroots, everyday people, we the policeman, we the postman, we the clerks ... can exercise our God-given rights to participate, be involved and make decisions about ourselves and our city," Davis said at a rally downtown in the Hotel Allegro, the Chicago Tribune reported.
A Democrat, Davis gave few policy details, the newspaper said, but vowed he would create jobs and economic development opportunities, and try to "save our children from lifetimes of drug use, abuse, (and) incarceration."
The Tribune said this is Davis' second try for the mayor's chair, attempting to replace outgoing Mayor Richard Daley. Daley said in September he wouldn't run for a seventh term.
But the congressman's announcement came after former White House chief of staff Rahm Emanuel kicked off his campaign Saturday. State Sen. James T. Meeks was scheduled to kick off his campaign Sunday night at the University of Illinois at Chicago.
Former U.S. Sen. Carol Moseley Braun and former Chicago Board of Education President Gery Chico also were gearing up for the mayor's race, the Tribune said.
The Chicago Sun-Times said Davis is the choice of a coalition of African-American politicians, religious and community leaders.