Medical science in antebellum America was organized around a paradox: it presumed African Americans to be less than human yet still human enough to be viable as experimental subjects, as cadavers, and for use in the training of medical students. By taking a hard look at the racial ideas of both northern and southern medical schools, Christopher D. E. Willoughby reveals that racist ideas were not external to the medical profession but fundamental to medical knowledge.

In this history of racial thinking and slavery in American medical schools, the founders and early faculty of these schools emerge as singularly influential proponents of white supremacist racial science. They pushed an understanding of race influenced by the theory of polygenesis—that each race was created separately and as different species—which they supported by training students to collect and measure human skulls from around the world. Medical students came to see themselves as masters of Black people's bodies through stealing Black people's corpses, experimenting on enslaved people, and practicing distinctive therapeutics on Black patients. In documenting these practices Masters of Health charts the rise of racist theories in U.S. medical schools, throwing new light on the extensive legacies of slavery in modern medicine.