The three Pullein-Thompsons sisters created a marvellous book in this and its counterpart, Black Beauty's Clan.
Each sister tells a story of a horse related to Black Beauty, whether a highwayman's horse, a carthorse, a hunter or a racehorse. Black Ebony, Black Velvet, Blossom and other horses spring to life and show us what times were like and how horses lived and worked.
I highly recommend these two books. I have seen one portion sold as a separate small book but all three tales complement each other and it would be very fiddly to try to collect all six separately, if they were even all published that way.
The Pullein-Thompsons were sisters who grew up between the wars, when horses were in daily use, and during the second world war they taught riding extensively as there was very little petrol so horses were put back in use. Their own story is told by themselves in Fair Girls On Grey Horses. They have all written horsey books but to my mind the best writer was Christine.
Another book like this was Son of Black Beauty by Phyllis Briggs.