The 1919 Kentucky Derby was supposed to be a battle between Billy Kelly and Eternal. Both colts had been the best of the juveniles the year before and both were highly regarded, so much so that notorious gambler Arnold Rothstein bet J.K.L. Ross, Billy Kelly’s owner, that Eternal would win. The bet was $50,000, a sum that would be closer to $700,000 in today’s money.

Ross had several three-year-olds in training, but his trainer H.G. Bedwell elected to bring Billy Kelly and Sir Barton, who hadn’t raced since his start in the Belmont Futurity the previous September, to Louisville for the big race. Billy Kelly had had a good spring, winning his last three races prior to arriving at Churchill Downs. Sir Barton, still a maiden, had shown quite a bit of speed in his workouts, but his long layoff, a result of his fight with blood poisoning the fall before, made him a question mark still. Bedwell saw Sir Barton’s speed as a potential tool for eliminating Eternal and making the way for Billy Kelly. Cal Shilling, a former jockey and now Bedwell’s assistant trainer, was advocating for Sir Barton, but Billy Kelly was Bedwell’s favorite. When the skies opened up over Louisville, Bedwell got antsy about starting the son of Star Shoot; he wasn’t sure how Sir Barton would handle the muddy track. But, at 5.10 pm on May 10, 1919, twelve horses went to the post, with Billy Kelly and Sir Barton coupled in the betting.

Sir Barton broke in front and no other horse got a nose in front of him throughout the mile and a quarter. This son of Star Shoot held off all comers, including his stablemate Billy Kelly, to win the Kentucky Derby in 2:09 4/5 on a track rated as heavy. He carried 112.5 pounds, his jockey Johnny Loftus unable to lose that last 2.5 pounds to get to 110 pounds, the weight maidens carried. The next day, Sir Barton went to Baltimore for the Preakness, set for May 14th, just four days after the Derby.

With his win in the Derby, Sir Barton set off on his path toward the first Triple Crown. Ross collected on his bet with Rothstein, a $50,000 check arriving soon after Billy Kelly beat Eternal while finishing second to his stablemate.