Sir Barton, winner of the 44th running of the Kentucky Derby at Churhill Downs, May 1919.
Sir Barton, foaled at Hamburg Place, Lexington, Kentucky, was the first Triple Crown winner in 1916.
Kentucky Derby and Preakness Stakes winner California Chrome will try to win the Triple Crown on June 7, 2014 at Belmont Park.
1930: Gallant Fox
Famous jockey "The Earl of Sande" up on his third Kentucky Derby winner Gallant Fox after the finish of the classic at Churchill Downs, Kentucky, May 19, 1930.
The Kentucky Derby winner Omaha is shown taking an easy gallop at Pimlico Race Track in Baltimore, May 8, 1935 .
1937: War Admiral
War Admiral poses beside trainer George Conway in Baltimore, Oct. 13, 1938.
Winner of racing’s Triple Crown in 1941, Whirlaway, the 12-year-old Calumet Farm stallion who became the first thoroughbred to earn more than $500,000 at the tracks, is led into a specially improvised stall for loading aboard the SS Elyssia in New York City, August 11, 1950.
Credit: Jacob Harris/AP
1943: Count Fleet
Count Fleet, with jockey Johnny Longden wearing the wreath of roses after winning the 69th running of the Kentucky Derby, May 1, 1943.
Wearing a garland of roses, Assault stands in the Kentucky Derby winner's circle, May 4, 1946.
Citation is shown in the winner's circle after taking a bow at Hollywood Park in Inglewood, California, on July 21, 1951. Citation, the first race horse to win $1 million, was retired to stud on July 20, 1951.
Jockey Ron Turcotte walks Secretariat towards the winners circle after they captured the Triple Crown by winning the Belmont Stakes, June 9, 1973.
1977: Seattle Slew
Jockey Jean Cruguet, aboard Seattle Slew, wins the Belmont Stakes in Elmont, New York, June 13, 1977.
Affirmed, with jockey Steve Cauthen, crosses the finish line to win the 104th running of the Kentucky Derby in Louisville, Kentucky, May 6, 1978.
California Chrome, the winner of the Kentucky Derby and Preakness, prepares for the final leg of the Triple Crown. No horse has swept the Derby, Preakness and Belmont since Affirmed in 1978.