Who was the last horse to win the Triple Crown before 1978?

The last horse to win the Triple Crown before 1978 was Omaha. This horse achieved this prestigious feat in 1935. Although Secretariat is widely celebrated for his Triple Crown victory in 1973 and is considered one of the greatest racehorses of all time, he came after Omaha. The Triple Crown consists of the Kentucky Derby, Preakness Stakes, and Belmont Stakes, and winning all three races is a remarkable achievement in thoroughbred racing. Omaha's win in 1935 remained unchallenged until Secretariat's historic win, which reignited interest in the Triple Crown races.