During the spring of 1916, Sir Barton, a chestnut colt with a blaze on his face, was born on John Madden's Hamburg Place in Lexington, Kentucky. His sire was Star Shoot, son of the English Triple Crown winner Isinglass, and his dam, Lady Sterling, daughter of a stallion known as Hanover.
Sir Barton's two-year-old season was unsuccessful. After not placing in the Tremont Stakes, the Flash Stakes, the U.S Hotel Stakes, and the Sanford Memorial Stakes, he was sold to Canadian Naval Commander John Ross for $10,000. Although Ross, who had recently inherited $12 million dollars from James Ross, his father, was new to thoroughbred racing, he owned several successful horses, including 1918's top two-year-old, Billy Kelly.
Sir Barton's trainer then became Harvey Bedwell, a cowpuncher from Oregon who had worked with horses since he was thirteen.
Sir Barton had an unpleasant disposition, disliking everybody except for his groom, Toots Thompson. Many people speculate that the reason for his bad temper was his hoof problems. Sir Barton's hooves were soft and shelly, and it pained him every time he ran, especially when his shoes fell off during a race, which they often did. Because of this, Bedwell inserted piano felt between Barton's shoe and hoof.
Furthermore, Barton hated workouts. He only pushed himself when other horses ran with him, so Bedwell was forced to tire several horses just to give Barton a workout.
"To get him fit you have to half kill him with work - and a lot of other horses as well," said Bedwell. Ross's son describes the horse as "an irascible, exasperating creature." Barton's temperent certainly didn't make him well liked.
Barton, ridden by Earl Sande for the first time, did not place in Hope Stakes. It was only to be expected. His next race, however, had a surprising outcome: he finished second behind Dunboyne. Nobody had expected Barton to even place. Even so, the accomplishment was simply dismissed as a stroke of luck, and no expected Barton to accomplish what would in his three-year-old season.