What does it mean to be human? To be human is, in part, to be physically sexed and culturally gendered. Yet not all bodies are clearly male or female. Bodies in Doubt traces the changing definitions, perceptions, and medical management of intersex (atypical sex development) in America from the colonial period to the present day. From the beginning, intersex bodies have been marked as "other," as monstrous, sinister, threatening, inferior, and unfortunate. Some nineteenth-century doctors viewed their intersex patients with disrespect and suspicion. Later, doctors showed more empathy for their patients' plights and tried to make correct decisions regarding their care. Yet definitions of "correct" in matters of intersex were entangled with shifting ideas and tensions about what was natural and normal, indeed about what constituted personhood or humanity. Reis has examined hundreds of cases of "hermaphroditism" and intersex found in medical and popular literature and argues that medical practice cannot be understood outside of the broader cultural context in which it is embedded. As the history of responses to intersex bodies has shown, doctors are influenced by social concerns about marriage and heterosexuality. Bodies in Doubt considers how Americans have interpreted and handled ambiguous bodies, how the criteria and the authority for judging bodies changed, how both the binary gender ideal and the anxiety over uncertainty persisted, and how the process for defining the very norms of sex and gender evolved. Bodies in Doubt breaks new ground in examining the historical roots of modern attitudes about intersex in the United States and will interest scholars and researchers in disability studies, social history, gender studies, and the history of medicine.