This is a review of the first edition from 1956, currently up on The Open Library for who knows how much longer.
This is a departure from Sam Savitt's usual style of books. Not only is it for a younger audience than usual, but there are also aùtobiographical touches. He has a portrait of his wife on the dedication page, and also draws a self-portrait.
The pencil drawings were done out in the field or in the stable as opposed to his studio. All of the drawings are detailed pencil sketches, although some are more detailed than others.
This is the true story of the first six months in the life of the foal this book is named after. She seems to've been a chestnut, according to the cover image (which is not available at The Open Library.) Savitt occasionally gives Step North, the dam, a touch of expressions worthy of Wesley Dennis.
Readers knowledgeable about horse racing in the 1950s will be amused to know that there is a donkey in the book named Nashua. Well, it amused me, anyway.
I did a quick Google to see whatever happened to Step-A-Bit. Although I found her pedigree, I didn't find anything else. Since her breeder/owner seemed so pleased that she figured out on her own how to jump, I wonder if she was never raced, and instead became a show or pleasure horse.