When he wasn't out riding horses, he was drawing them, taking great interest in their bone structure and conformation.
Anderson started his career by illustrating for other authors, but eventually began developing texts to accompany his realistic and lively black and white drawings.
He would even go on to write Heads Up, Heels Down as a training tool for young horse lovers.
By the end of Anderson's life, he had written and illustrated over thirty-five horse books, and had also created covers for the Saturday Evening Post.
Anderson is the namesake for Andy's Summer Playhouse, a youth theater in Wilton, New Hampshire.