The Triple Crown of Thoroughbred Racing (although sometimes shortened to Triple Crown, the full name is used to avoid possible confusion with other sports) consists of three races for three-year-old Thoroughbred horses. Winning all three of these Thoroughbred horse races is considered the greatest accomplishment of a Thoroughbred racehorse. The term originated in mid-19th century England. However, different nations where thoroughbred racing is popular each have their own Triple Crown series.
Contributions by Handicapper, Agustin.Torero, and Cgoodwin.