This article discusses the collection and use of enemy skulls and other bones as trophies by soldiers and their supporters in the American Civil War. This behaviour was condemned at the time as that of ‘savages’. However, the author argues that it was a local symptom of the shifts taking place after the Enlightenment in the ways in which human diversity was conceptualized. Civil War soldiers who collected and displayed their enemies’ remains did so for some of the same reasons that comparative anatomists had begun to collect, display and study such objects at the time. They, too, assumed that the fundamental material evidence of human differences lay under the skin, in the bones and, above all, in the skull.