The three races of the American Triple Crown are:
The Kentucky Derby, Churchill Downs, Louisville, Kentucky; the first Saturday in May; 1-1/4 miles.
The Preakness Stakes, Pimlico Race Course, Baltimore, Maryland; on Saturday two weeks after the Derby; 1-3/16 miles.
The Belmont Stakes, Belmont Park, Elmont, New York; on Saturday three weeks after the Preakness; 1-1/2 miles.
Lots of other countries have horse racing triple crowns, as well.
See my Hubs: "Why National Thoroughbred Triple Crowns Are Very Difficult to Win" and "What Does Triple Crown Mean In Horse Racing" and "The Kentucky Derby and Why Secretariat Is Its Greatest Champion" for much more information!!
Thanks for asking those questions!