Justin Morgan Had a Horse, by Marguerite Henry

You'd think by now I'd have learned not to judge a book by its cover.  I went through a stage in 2nd-3rd grade where I really tried (I really tried, people!) to like the Marguerite Henry horse books because everyone liked them and they'd won awards and HORSES!  Who doesn't like horses?  I liked horses!  But I didn't like the books, for whatever reason.  So when this book came up next on my list I'll admit I was transported back into childhood with a sense of dread.  Completely misplaced dread.  This book was pretty awesome!  I'm so sorry for having doubted you.

Although Justin Morgan was the owner of the "first" Morgan horse, he isn't our book's protagonist.  The book actually follows Joel Goss, a student of Morgan's, who is present when Li'l Bub, the horse in question, is given to Morgan as partial payment on a debt owed.  Although Li'l Bub is small and shows none of the signs that he'll ever be remotely useful, Joel takes to him immediately.  Justin Morgan sees that Joel is smitten, and as he has neither time nor inclination to deal with the horse himself around his teaching schedule, he asks Joel to gentle the horse for him.  Joel is apprenticed to the miller around this time and must attend school in the evenings, but after school lets out he has a few scarce hours of Vermont daylight remaining to work with Li'l Bub.

After Li'l Bub has been successfully gentled, much to Joel's dismay, he is rented out to a man to help him clear land.  Li'l Bub soon proves himself as an able puller, and eventually gains a widespread reputation for both pulling and racing, even beating out two purebreds who had traveled from New York just to beat him.  With this reputation firmly in hand (hoof?), Justin Morgan eventually sells Li'l Bub so that he is able to pay his outstanding debts and buy needed supplies (including a harpsichord) for his schoolhouse.  The remainder of the story follows Joel through his apprenticeship into adulthood, trying to locate his beloved horse so that he can eventually purchase him for his own.  Over the years the horse changes hands many times (and upon Morgan's death, his name as well) until he and Joel are eventually reunited.

A very well-told story!