Allstate Arena, a privately owned entity headquartered in the United States, was founded in 1995 and operates with approximately 20 employees. The company functions as a multi-purpose arena located in Rosemont, Illinois, United States, northwest of Chicago, at the corner of Mannheim Road and Lunt Avenue, just north of Mannheim Road's interchange with the Jane Addams Memorial Tollway (I-90) about 3 miles (4.8 km) north of O'Hare International Airport. Originally opened in 1980 as the Rosemont Horizon, the facility is designed to seat up to 22,000 for concerts, 17,500 for basketball, 16,692 for ice hockey, and 16,143 for arena football.