A look back at historical events on this day in Thoroughbred racing

October 4, 1762—Nineteen members of England's Jockey Club announced an agreement at Newmarket to register their racing colors for purposes of distinguishing runners among a field of horses. The Duke of Devonshire chose "straw," and the color, still registered for the family, is the oldest continuously used color in racing.

October. 4, 1970--Nijinsky II's 11-race winning streak came to an end when he ran second to Sassafras in the Prix de l'Arc de Triomphe.

October 4, 1972--Secretariat worked a mile in 1:37 in preparation for the Champagne Stakes on October 14.

October 4, 1980--Less than an hour before post time, Spectacular Bid was scratched from the Jockey Club Gold Cup (G1), the race that was to have been his last. Trainer Bud Delp claimed that "Bid" had a slight leg injury, but refused to allow a veterinarian to examine the horse and insisted he be retired. Despite this ignoble end to his career, Spectacular Bid's 1980 racing season was perfect: he won each of his nine starts, all of them stakes, and was subsequently voted Horse of the Year.

October 4, 1989--Secretariat, 1973 Triple Crown winner and Horse of the Year in 1972 and '73, was euthanized at Claiborne Farm, in Paris, Kentucky, after suffering a severe case of laminitis. He was 19.