Seattle Slew was an American thoroughbred race horse…..who won the Triple Crown in 1977….as he was the tenth of twelve horses to accomplish the feat. He is the only horse to have won the Triple Crown while having been undefeated in any race previous. In the Blood-Horse Magazine list of top 100 US racehoses of the 20th Century….Seattle Slew was ranked ninth. Joe Hirsch of the Daily Racing Form wrote: “Every time he ran he was an odds-on favorite, and the response to his presence on the racetrack, either for a morning workout or a major race, was electric. ‘Slewmania’ was a virulent and widespread condition.