How many Triple Crown winners in American horse racing have there been between 1919 and 2017?

All 12 Triple Crown winning thoroughbreds have done it since 1919.

To pull this feat off, three-year-old horses must win the Kentucky Derby, Preakness and The Belmont in succession. It seems simple, but the low number of animals to achieve this distinction speaks volumes of its difficulty.

The Triple Crown series technically became possible with the inauguration of the Kentucky Derby in 1875. The Belmont Stakes was first run in 1867 and the Preakness in 1873. Daily Racing Form writer Charles Hatton is commonly credited with originating the term to reference these races in 1930, although they were referred to by that name at least as early as 1923. Since 1931, the order of Triple Crown races has been the Kentucky Derby first, followed by the Preakness Stakes, and then the Belmont Stakes. Prior to 1931, the Preakness Stakes was run before the Kentucky Derby eleven times.

Sir Barton was the first Triple Crown winner. But there wasn't another winner until 1930. Between 1930 and 1948, seven horses (Gallant Fox, Omaha, War Admiral, Whirlaway, Count Fleet, Assault, Citation) succeeded. It would be 25 years until another horse came along. What a horse it was. In 1973, the chestnut colt Secretariat (pictured), considered the greatest horse in history, won the Triple Crown setting race records in all three events that still stand. Seattle Slew and Affirmed . It was 37 years before American Pharoah won in 2015.