Guaranteed Rate Field is a baseball park in Chicago, Illinois. It is the home field of the Major League Baseball team called the Chicago White Sox. It opened in 1991, replacing historic Comiskey Park. Before U.S. Cellular, a wireless telephone carrier, bought naming rights in 2003, with the stadium then being renamed U.S. Cellular Field, the ballpark was known as "New Comiskey Park" or just "Comiskey Park", in honor of the old park.