Written in permanent marker, racial epithets and phrases such as "whites only" appeared on the walls of common areas, including hallways and stairwells, of the University Hall dormitory, the Chicago Tribune said. Graffiti was also found on the outside of the dorm as well as two other buildings.
DePaul University spokesperson Denise Mattson told WBBM Radio the incident was an assault on the university's values.
Mattson said the campus has been politically charged since late January when a new campus organization, the DePaul Conservative Alliance, conducted an "affirmative action bake sale" at which blacks were charged less than whites.
"That certainly created some dialogue about affirmative action policies and practices about minorities on campus," Mattson said.
A university spokesman said the alliance was not suspected in the graffiti incident.