While establishing himself as one of America's leading jockeys, he was diagnosed with what is now known as type 1 diabetes. Only a few years earlier, before the discovery of insulin, such a diagnosis would have been fatal. Because of his condition, and the nature of diabetes management in the 1930s and 1940s, Woolf had to regulate his weight to avoid rapid dieting. His racing success allowed him to accept only a few mounts each week, riding only 150–200 races each year compared to as many as a thousand rides other jockeys might undertake, and for years he maintained top physical condition. Despite his limited number of races and a relatively short career, Woolf won ninety-seven major stakes races around the United States, including the Hollywood Gold Cup Stakes, the American Derby and the Belmont Futurity Stakes three years running. He made history in 1935 when he rode Azucar to victory in the first $100,000 horse race, the Santa Anita Handicap, defeating such greats as Equipoise and Twenty Grand. Woolf finished second twice at the Kentucky Derby and won the 1936 Preakness Stakes. He is remembered for his tactical performance in the 1938 match race when he rode Seabiscuit to victory over the heavily favored U.S. Triple Crown champion, War Admiral, in the Pimlico Special at Baltimore, based on advice from his friend, Seabiscuit's injured regular jockey Red Pollard. When asked which was the best racehorse he had ever ridden, Woolf answered immediately, "Seabiscuit". During the running of the fourth race at Santa Anita Park on January 3, 1946, Woolf fell from his horse, Please Me, as he rounded the clubhouse turn. Suffering from a concussion, he was taken to the hospital, where he died the following day. The jockeys in the race and the track stewards reported that they had not witnessed any incident during the race to have caused such a fall. Most observers think his diabetic condition may have resulted in his suffering a dizzy spell or fainting. Woolf was buried at the Forest Lawn Memorial Park Cemetery in The Great Mausoleum, Gardenia Terrace, the Sanctuary of Providence, Mausoleum Crypt 9707 in Glendale, California. Western singing star Gene Autry sang at his funeral service. The death at age 35 of one of the country's best and most respected jockeys, and a favorite of fans, led to the creation of the George Woolf Memorial Jockey Award.