Two phenomena collided in the mid-nineteenth-century Atlantic World: first, chattel slavery ended, after expanding in some parts of the hemisphere, ushering in post-emancipation transitions across the Americas. At the same time, in parts of Europe and the Americas, asylums—increasingly operated by the state—began implementing new psychiatric methods that emphasised transforming patients’ moral character rather than pacifying them through physical restraint. Historians of asylums have not always connected these phenomena, as scholars have focused more on Europe and the US northeast than on former slave societies. Yet, there is growing attention among historians of slavery and post-slavery societies to the incarcerating institutions that grew during the final decades of slavery and the early post-emancipation period. Wendy Gonaver’s The Peculiar Institution and the Making of Modern Psychiatry 1840–1880 is an important addition to this scholarship.