Thirteen horses have won the Triple Crown in American Thoroughbred racing history. Here's a look at the winners and the history of the Triple Crown:

The Triple Crown is an accomplishment that a select group of horses has achieved throughout history. When a horse wins all "jewel" races in a single season -- the Kentucky Derby, Preakness Stakes and Belmont Stakes -- it's widely regarded as one of the highest honors in all of sports.

A search of pedigrees determined that every horse in the 151st Kentucky Derby is related to arguably the greatest race horse ever