I am looking for a children’s/YA horse story from the late fifties or early sixties.  It features a somewhat broken down horse named Black Baldwin, who was bought/adopted by an eleven year old girl desperate to have a horse.  She rehabilitates him and eventually wins second prize in some kind of horse show event.  The book had small pen and ink drawings throughout.  I don’t remember the book jacket though, I believe it had one.

I searched for a long time thinking the horse’s name was the title of the book.  Either it is and every copy is long gone, or there is some other title.