Issues germane to animal history and military history intersect in the study of cavalry horses and their riders during the American Civil War. Animal historians should understand that warfare created a very different experience for horses than was true of their peacetime experience. Military historians should understand that horses were not just tools of war but sentient creatures with needs and emotions of their own. Weaponized equines exercised a degree of agency by exerting some control over their situations. The military system and battle severely stressed horses and men. Repetitive riding affected cavalrymen and horses in ways that resulted in serious health problems. Nevertheless, the war experience fostered bonds of affection between animals and humans in many cases while leading to callous abuse in many others. It also led to an enhanced appreciation for animals among cavalrymen who had bonded with their mounts, possibly promoting awareness of animal rights after the conflict.