Henry Stull was born in Hamilton, Ontario as the son of a coach and hansom cab driver in 1851. He aspired to become a professional actor, but eventually got a job with a Toronto insurance firm. Hoping to find more acting opportunities, he headed for New York City in 1872. However, he ended up an illustrator and cartoonist on the staff of Leslie's Illustrated Weekly.
He was a sports illustrator for The Spirit of the Times for 14 years and in his spare time he made racehorse portraits on commission. By the late 1890s he was one of the top horse portraitists in the country. He did comic strip work for the Philadelphia publication Our Continent in 1883.