The Triple Crown of horse racing is a series of races contested each spring for three-year-olds that include the Kentucky Derby, Preakness Stakes and Belmont Stakes. Only 12 horses have managed to sweep all three jewels.

The first jewel of the Triple Crown is the Kentucky Derby, run on the first Saturday of May at Churchill Downs in Louisville, Kentucky. First contested in 1875, the race is known as the two most exciting minutes in sports. The race is contested at 1 ¼ miles.

Two weeks later the best three-year-olds head to Baltimore, Maryland for the Preakness Stakes at Pimlico Race Course for the second jewel of the Triple Crown. The race is the shortest of the three races, contested at 1 3/16 miles.

The final jewel of racing’s Triple Crown is the Belmont Stakes, a 1 ½ mile marathon contested at Belmont Park in Elmont, New York.

Until American Pharoah did it in 2015, the last horse to sweep all three races had been Affirmed in 1978. The colt was trained by Laz Barrera and ridden by jockey Steve Cauthen. The colt was the third of the 1970s to win the Triple Crown, following Secretariat and Seattle Slew.

The Triple Crown Winners

2015: American Pharoah
1978: Affirmed
1977: Seattle Slew
1973: Secretariat
1948: Citation
1946: Assault
1943: Count Fleet
1941: Whirlaway
1937: War Admiral
1935: Omaha
1930: Gallant Fox
1919: Sir Barton