Iron Constitution

Iron Constitution (1974–1989) was an American Thoroughbred racehorse owned by Harry T. Mangurian Jr.'s Mockingbird Farm of Ocala, Florida. Bred by Thomas Mellon Evans, a successful financier and horse breeder, Iron Constitution was sired by Iron Ruler, a son of Never Bend, and out of the mare Water Cress, daughter of Hail to Reason.

During his short racing career (from late in his two-year-old season until mid-career at four), Iron Constitution achieved notable success. He broke his maiden in his third start and won the 1977 Withers Stakes at Aqueduct Racetrack under jockey Jorge Velásquez, finishing in 1:37.00. Three weeks later, he ran second to undefeated Kentucky Derby winner Seattle Slew in the 1977 Preakness Stakes, despite being a 31-1 longshot.

Iron Constitution continued to perform well in other races, including placing second in the Grade 1 Jersey Derby and the Woodlawn Stakes on turf at Pimlico Race Course. He also showed in third place in several other stakes races. At age four, he placed second in his final stakes race, the Cinema Handicap.

In later life, Iron Constitution became a stud but was euthanized in June 1989 after sustaining a fractured leg at Graywood, Livonia Center, New York, where he spent his stud career.