This novel is a fictionalised account of a famous Union Cavalry raid during the American Civil War. It was made into a film starring John Wayne back in the 1950's but I managed to get my hands on a recent reprint published in 2001.
This is a terrific read. Even though it is highly fictionalised (all the characters names are changed) it does lean heavily on the facts of Grearson's heroic raid . Apart from being well written and a great read it also gives a great flavour of the this the first modern war. Highly recommended if you can get your hands on a copy.