Born in Port Chester, New York in 1896, Leonard decided early in his childhood that he wanted to be a cartoonist while he made copies of Buster Brown, Happy Hooligan, Little Nemo and The Katzenjammer Kids, eventually creating his own characters.

After his high school graduation, Leonard took a job as a bookkeeper at a local factory, where he also drew cartoons for the plant's house organ.

[1][2] Returning from the service, Leonard designed a new type of suction sole basketball shoe for a sporting goods firm, which eventually hired him as a salesman.

He was in his early twenties, working as a traveling salesman, when he met cartoonist Clare A. Briggs on a train between Sioux City and Omaha and showed him the sketch pad he always carried.

[3] Briggs referred him to Chicago Tribune editorial cartoonist Carey Orr, who suggested Leonard take the C. L. Evans correspondence course in cartooning.

Appearing in more than 300 newspapers at the height of its success, the strip continued under Leonard for the next three decades, assisted by Mart Bailey and Morris Weiss with lettering by Tony DiPreta.

[5] In 1951, Leonard and Bishop left Florida for Washington's Carlton Hotel, where they joined other members of the National Cartoonists Society for breakfast on November 6 with Harry Truman.