Sloan was born in Bunker Hill, Indiana, near Kokomo, the son of a Union Army soldier. He was a tiny and frail child, and after his mother died when he was five, his father sent him to live with a nearby family. He was still a young boy when he struck out on his own, taking jobs in the nearby gas and oil fields. For a time he ended up working at a horse racing stable in St. Louis, but later in Kansas City was employed by a thoroughbred horse trainer who encouraged him to take advantage of his diminutive stature and become a jockey.
By 1886, Sloan was working at Latonia Race Track in Covington, Kentucky, where trainer Sam Hildreth gave him the opportunity to ride one of his horses. Sloan’s performance was not impressive, and his horse finished in the back of the pack. However, he persisted and a few years later was riding at the Fair Grounds Race Course in New Orleans, and on March 6, 1889, scored his first win there.
In 1893, Sloan went to race in northern California where he enjoyed considerable success. In 1896 he moved to New York City after being hired by “Pittsburgh Phil”, where within a short time he was the dominant rider in the thoroughbred racing circuit on the East Coast. Despite his many career victories, Sloan said that Hamburg (1895–1915) was the only great horse he ever rode. Sloan took over as jockey for Hamburg when the horse’s career was near its end after the three-year-old had been soundly defeated in the Belmont Stakes. Ridden by Sloan, the horse won the Lawrence Realization, easily defeating Kentucky Derby winner Plaudit, then scored the most impressive win of his career in the 2¼-mile American Brighton Cup. Such were Sloan’s abilities that in 1896 he won nearly 30% of all his races, increased it to 37% in 1897, and upped it to an astonishing 46% in 1898.
Charles F. Dwyer, a close friend and son of prominent racehorse owner Mike Dwyer, was part of a syndicate that backed Sloan’s mounts when he rode in England. Racing there on September 30, 1898, Sloan rode five consecutive winners at the Newmarket Racecourse. It was Sloan who popularized the forward seat style of riding, or the “monkey crouch” as the British called it, when he began riding there in 1897. Initially laughed at, his style revolutionized the sport worldwide. (Although he did not invent it. The “American Seat” of short stirrups and crouching over the horse’s neck and withers was used in the colonies as far back as the quarter mile dashes along tracks cut in the wilderness as well as being the preferred riding style of the Native Americans. Not only that, but two years before Sloan rode in England, the African American jockey, Willie Simms had ridden exactly that way taking England’s Crawfurd Plate (sic) at Newmarket against England’s finest bolt-upright riders.)
Returning to England the following year he won a number of important races including the 1899 1,000 Guineas aboard Sibola and in 1900 the Ascot Gold Cup riding Merman for owner, Lily Langtry. The prestigious Derby was a race that Sloan always felt he would have won, had it not been for a terrible tragedy. In the 1899 race, his horse Holocauste took the early lead, and rounding Tattenham Corner Holocauste and Flying Fox, winner of the 2,000 Guineas, were racing head-to-head in front of the rest of the field. At that point in the race Sloan said he was still holding back on the horse, in preparation for a full-out drive down the straight, when his horse stopped abruptly and collapsed to the ground with a shattered pastern. Holocauste had to be put down while Flying Fox went on to win the race. Later that year Flying Fox won the St. Leger to become the 1899 Triple Crown Champion.
In 1900, Edward, Prince of Wales offered Sloan the job to ride for his stable in the 1901 racing season. Sloan’s success on the racetrack, combined with a flamboyant lifestyle filled with beautiful women, made him one of the first to become a major international celebrity in the sport. He hung out with the likes of Diamond Jim Brady and traveled with a personal valet and a trunk full of clothes. His reputation was such that he was the “Yankee Doodle” in the George M. CohanBroadway musical Little Johnny Jones and the basis for Ernest Hemingway‘s short storyMy Old Man. Although Sloan’s racing career was spectacular, it was relatively short, ending by 1901 under a cloud of suspicion that he had been betting on races in which he had competed. Advised by the British Jockey Club that they would not renew his license, he never rode for the Prince of Wales. The ban in Britain was maintained by American racing authorities, and Sloan’s jockey career came to an end.