The Tenth Horse is the story of cavalry officer Clay Jordan and his beautiful wife Kathleen, who have been separated during the Civil War but are reunited afterward. Clay accepts an appointment to the newly formed all black Tenth Cavalry Regiment. They join the regiment in Kansas where Clay is given command of B Troop and starts training the raw recruits. The regiment is assigned the task of controlling the Kiowa and Comanche Indians recently forced onto a reservation in Indian Territory. The Tenth has to overcome many obstacles, including racism, but it earns the respect of the Indians, who call them buffalo soldiers. Kathleen, who originally had misgivings about being an Army wife, becomes the nurse to the troopers and is so revered by them that they will go to great lengths to protect her. The Tenth gets involved in the bloody situation in which Kiowa and Comanche raiders from the reservation are raping and plundering the Texas frontier and are retreating to the protection of the reservation. General William T. Sherman comes to the frontier to find a solution to the problem, and with the help of the Tenth, he does so.In the end the Tenth Horse becomes a proud regiment, and Clay and Kathleen play an important role.