On June 9, 1973, a bright chestnut horse with three white socks and a narrow white blaze crossed the finish line at Belmont Park in Elmont, New York to become America’s ninth Triple Crown winner and the first since a horse named Citation in 1948. The horse was Secretariat, and he is considered by many to be the greatest thoroughbred racehorse of the 20th-century. Secretariat arrived in New York for the 105th running of the Belmont Stakes having already conquered the Kentucky Derby and Preakness Stakes—both in record time. He entered…