Table:
text: Triple Crown of Thoroughbred Racing
United States Triple Crowns
Triple Crown winners
Year_ Winner Jockey Trainer Owner_ Breeder_
1919 Sir Barton Johnny Loftus H. Guy Bedwell J. K. L. Ross 
1930 Gallant Fox Earl Sande Jim Fitzsimmons Belair Stud Belair Stud
1935 Omaha Willie Saunders Jim Fitzsimmons Belair Stud Belair Stud
1937 War Admiral Charley Kurtsinger George H. Conway Samuel D. Riddle Samuel D. Riddle
1941 Whirlaway Eddie Arcaro Ben A. Jones Calumet Farm Calumet Farm
1943 Count Fleet Johnny Longden Don Cameron Fannie Hertz Fannie Hertz
1946 Assault Warren Mehrtens Max Hirsch King Ranch King Ranch
1948 Citation Eddie Arcaro Horace A. Jones Calumet Farm Calumet Farm
1973 Secretariat Ron Turcotte Lucien Laurin Meadow Stable Meadow Stud

text: Triple Crown of Thoroughbred Racing
United States Triple Crowns
Triple Crown winners
Year_ Winner Jockey Trainer Owner_ Breeder_
1977 Seattle Slew Jean Cruguet William H. Turner, Jr. Karen L. Taylor Ben S. Castleman
1978 Affirmed Steve Cauthen Laz Barrera Harbor View Farm Harbor View Farm

Question: What year did Triple Crown of Thoroughbred Racing first see a Triple Crown winner?