Standing second from left is Karen Taylor, owner of Seattle Slew. Better Self, on rail, ridden by Warren Mehrtens, was second, six lengths away. (AP Photo)

American Pharoah crosses the finish line to win the 147th running of the Belmont Stakes horse race at Belmont Park, June 6, 2015, in Elmont, N.Y. Kleberg, Jr. Sir Barton, foaled at Hamburg Place, Lexington, Ky., was the first Triple Crown winner in 1916.

AP Photo

Whirlaway – 1941

Whirlaway is draped with the floral tribute in the winner’s circle at Belmont Park, N.Y., June 7, 1941, after winning the Belmont Stakes race of the Triple Crown with jockey Eddie Arcaro. American Pharoah is the first horse to win the Triple Crown since Affirmed won it in 1978.

AP Photo

Gallant Fox – 1930

Gallant Fox, with jockey Earl Sande up, wears the roses after winning the 1930 Kentucky Derby.

Focus on Sport/Getty Images

Seattle Slew – 1977

Jockey Jean Cruguet sits on Seattle Slew in the winners circle after winning the Belmont Stakes in Elmont, N.Y., June 1, 1977. Kleberg, Jr., Jockey Warren Mehrtens, and owner Robert J. Kurtsinger, June 5, 1937.

AP Photo

Sir Barton – 1919

Sir Barton, winner of the 44th running of the Kentucky Derby at Churchill Downs in May 1919. AP Photo

Assault – 1946

Wearing a garland of Roses, Assault stands in the Kentucky Derby winner’s circle, May 4, 1946, in Louisville, Ky., with Mrs. Citation won the race and the Triple Crown. Robert J. of King Ranch, Texas.

AP Photo

Citation – 1948

Citation, ridden by Eddie Arcado, races home an easy winner in the $100,000 added Belmont Stakes at Belmont Park race track in Elmont, N.Y. 3, who takes the lead during the Belmont Stakes, June 10, 1978, to win the Triple Crown at Belmont Park in Elmont, N.Y.

AP Photo

Omaha – 1935

William Woodward’s Kentucky Derby winner, Omaha, gallops in his last hard workout prior to the $25,000 at Pimlico Race Track in Baltimore, May 10, 1935.. on June 12, 1948. Trainer Ben Jones holds the bridle.

AP Photo

Count Fleet – 1943

Jockey Johnny Longden is seated on Count Fleet in New York, May 22, 1943. Longden rode Count Fleet thoroughbred racing’s Triple Crown, with victories in the Kentucky Derby, Preakness and Belmont Stakes.

AP Photo

Seth Wenig/AP Photo

Affirmed – 1978

Jockey Steve Cauthen rides on Affirmed, No. Escadru, left, was third. Third from left is her husband, Mickey.

AP Photo

Secretariat – 1973

Jockey Ron Turcotte walks Secretariat towards the winners circle after they captured the Triple Crown by winning the Belmont Stakes at Belmont Park in Elmont, N.Y., June 9, 1973.

AP Photo

War Admiral – 1937

War Admiral with C