Born in Washington, D.C., as a child Bransom started sketching animals he saw in his backyard and at the National Zoo.
[2] He began his career as a technical draftsman for the U.S. Patent Office when he was 13 years old.
[3] After moving to New York, his talent as a wildlife artist was recognized while creating studies of the animals at the Bronx Zoo.
[4] His earliest commissions were covers for the Saturday Evening Post[4] and illustrations for editions of Kipling's Just So Stories and Grahame's The Wind in the Willows.
[5] Bransom was awarded the Benjamin West Clinedinst Memorial Medal,[4] and his works are included in the collection of the National Museum of American Illustration at Newport, Rhode Island.