Arlington International Racecourse is a horse race track in the Chicago suburb of Arlington Heights Illinois. Horse racing in the Chicago region has been a popular sport since the early days of the city in the 1830s and at one time Chicago had more horse racing tracks six than any other major metropolitan area.Arlington International Racecourse was founded as Arlington Park by California businessman Harry D. Curly.Arlington International Racecourse is a horse race track in the Chicago suburb of Arlington Heights Illinois. Horse racing in the Chicago region has been a popular sport since the early days of the city in the 1830s and at one time Chicago had more horse racing tracks six than any other major metropolitan area.Arlington International Racecourse was founded as Arlington Park by California businessman Harry D. Curly.