The FBI rescued more than 100 children in a nationwide sex trafficking raid; two of them were in Chicago.
The sweep, dubbed Operation Cross Country, covered 76 cities over three days.
Almost all of the victims are girls in their teens; no details were given about the victims found in Chicago.
150 people were arrested for forcing the girls into child prostitution; some were forced to work at sites of major sporting events like the Super Bowl and the Final Four.
Authorities say children without family ties are especially vulnerable.
The FBI says this newest sweep has been the most successful in identifying both victims and their pimps.