Which horse was the first to win the American Triple Crown?

Sir Barton was the first horse to win the American Triple Crown.

He achieved the feat in 1919 by winning the Kentucky Derby, Preakness Stakes and Belmont Stakes. The races were not formally grouped under the name “Triple Crown” at the time; that label became widely established later, after Gallant Fox won all three in 1930.

Sir Barton’s accomplishment was especially notable because he won the Kentucky Derby and Preakness Stakes only four days apart. He then won the Belmont Stakes by five lengths, completing the three-race sequence. Sir Barton was owned by Commander J. K. L. Ross and trained by H. Guy Bedwell.

People sometimes identify Gallant Fox as the first Triple Crown winner because he was the first horse officially promoted under the term. Sir Barton, however, completed the same three-race sweep eleven years earlier. The National Thoroughbred Racing Association and racing historians recognize his 1919 achievement as the first American Triple Crown.