There was an exception in 2020, when it was shortened to one-and-an-eighth of a mile and became the first Triple Crown race to be held following shutdowns related to the COVID-19 pandemic.
One of the reasons there have only been 13 horses to complete the Triple Crown by winning the Kentucky Derby, the Preakness Stakes and the Belmont Stakes in the same year is because of the challenge presented by the longer distance in the final contest.
The first winning time that was posted after the race was lengthened from a mile-and-three-eighths was 2:32.20 by Crusader. In 1930, Gallant Fox completed his Triple Crown by bettering the record at 2:31.60. This only stood for a year though as in 1931 Twenty Grand became the first horse to break the two-and-a-half-minute barrier by posting a time of 2:29.60.
In 1934, Peace Chance ran at 2:29.20, which lasted until 1937 when War Admiral, on his way to winning the Triple Crown, lowered the record to 2:28.60. Another Triple Crown winner, Count Fleet, ran 2:28.20 in 1943, and Citation equalled the time as he became the last horse for 25 years to complete the sweep of the races for three-year-olds in 1948.
Gallant Man, who had suffered an upset defeat in the Kentucky Derby earlier in the season, shattered the previous Belmont Stakes record by over a second and a half by running the race in 2:26.60 in 1957, a time that stood until one of the most spectacular sporting feats of all-time. While that statement may sound like hyperbole, with sports-related records frequently set and broken, what occurred at Belmont Park in 1973 still stands the test of time.
Secretariat's record 1973 run
Secretariat was Horse of the Year in 1972 and, after a third-place finish in the Wood Memorial, had won the first two jewels of the Triple Crown in 1973. He was looking to become the first horse to accomplish the greatest feat in horse racing since Citation in 1948. He had set a record in the Kentucky Derby by beating Sham by two-and-a-half lengths, a feat he duplicated in the Preakness Stakes, defeating the same horse by the same margin in record time.
Despite Secretariat's dominance in the first two races, nothing prepared the horse racing world for what took place in the Belmont Stakes. This was partly because he was the eighth horse since Citation to have won the first two races of the Triple Crown going into the third and final race. There were only five horses entered, including Sham, with Secretariat starting from the second post position at odds of 1/10.
As the race progressed, it was obvious that Secretariat would become the ninth Triple Crown winner, but as his lead continued to increase, it was also apparent that something more historic was occurring. Ultimately, Secretariat won by a record 31 lengths and set a Belmont Stakes and American one-and-a-half mile race record with a time of 2:24.00.
To put his accomplishment into perspective, the best time since 1973 is A.P. Indy's 2:26.13 in 1992. Secretariat's record time and margin of victory have stood for 48 years and could well stand for 48 more.