Affirmed had the distinction of being the eleventh horse to win the Triple Crown Trophy – awarded for winning the Kentucky Derby, the Preakness Stakes and the Belmont Stakes – in 1978 and was the last horse to do so for 37 years. He was also named American Horse of the Year in 1978 and 1979, American Champion Two-Year-Old Male Horse in 1977, American Champion Three-Year-Old Male Horse in 1978 and American Champion Older Horse in 1979.
Bred and owned by Louis and Patrice Wolfson, in the name of Harbor View Farm, Florida and trained by Laz Barrera, Affirmed is remembered for his rivalry with Alydar. In total, the pair met ten times during their two-year-old and three-year-old campaigns, including in all three Triple Crown races. In 1977, Affirmed won seven of his nine races, including victories over Alydar in the Hopeful Stakes, the Belmont Futurity and the Laurel Futurity. On his other two starts, Affirmed finished second to Alydar in the Great American Stakes and the Champagne Stakes.
In 1978, Affirmed won his first eight starts, including victories over Alydar in all three Triple Crown races by ever decreasing margins. He won the Kentucky Derby by 1½ lengths, the Preakness Stakes by a neck and the Belmont Stakes by a head. Steve Cauthen who, as an 18-year-old, rode Affirmed in all three races, later said, “He was basically the best horse I ever rode, the most intelligent. He was just a horse of tremendous courage. He loved to race. He was a great horse to ride.”
Later that season, Alydar earned scant consolation when awarded the Travers Stakes at Saratoga on the disqualification of Affirmed who, in the absence of the injured Cauthen, was ridden by Laffit Pincay Jr. Pincay said afterwards, “It was a mistake on my part. My horse opened up so fast I thought I was clear. I regret it. “
When he was retired to stud in 1979, Affirmed had won 22 of his 29 races, including 14 stakes races, and over $2.3 million in prize money. He was humanely euthanised, as a 26-year-old, in 2001, after becoming increasing infirm. His co-owner, Patrice Wolfson, said at the time, “Affirmed will forever stand with those who exemplify the word ‘champion’ in thoroughbred racing. We cannot begin to imagine how much we will miss him.”