Black Beauty, by Anna Sewell. Every little girl worth her salt read this book, which was responsible for the creation of the RSPCA and its American cousin, the SPCA. If you don't know the story, Beauty was a carriage horse who had to be sold when his owners were forced to move. He then became a cab horse, and he observed the misfortunes of the animal world, and the sad endings of two of his old stablemates and best friends. Happily, through twists of fate, he finally ends up happily retired.