Broomspun got a late start to his three-year-old season, making his sophomore debut in an allowance race at a mile and one eighth at New York's Aqueduct Racetrack.
Later that year, after the Derby runner did not return two weeks later in Baltimore, trainer James Rowe entered Broomspun in the second jewel of Triple Crown, the Preakness Stakes.
In the final strides, he was ridden out hard by jockey Frank Coltiletti to hold for the win by three quarters of a length over a hard-charging filly named Polly Ann.
The 3-year-old son of Broomstick and Spun Giass, who is the property of Harry Payne Whitney, the New York City sportsman, won the Classic Preakness from a field of 14 strong competitors, the best three-year-olds in the country."
While competing in the June 18, 1921 Carlton Stakes at New York's Aqueduct Racetrack, jockey Clarence Kummer felt Broomspun's leg give on his first stride at the start of the race and pulled him up after four furlongs.