This is the history of the foundations of modern carceral institutions in Ontario. Drawing on a wide range of previously unexplored primary material – including the papers of prison inspectors and officials and the correspondence of those who wrote to the authorities – Peter Oliver provides a narrative and interpretative account of the penal system in nineteenth-century Ontario. In a century of massive social change, the penal system remained rural, local, decentralized, and resistant to transformations that were affecting other areas of society. Despite the efforts of reformers, neither the political elites nor Ontarians in general paid much attention to the inadequacies of a system plagued by neglect, penny-pinching, and the vagaries of local control. In the 1830s, the Kingston penitentiary and punishment by incarceration became the cornerstones of the system, and these elements, however flawed, dominated the Ontario correctional system until the late twentieth century. 'Terror to Evil-Doers' focuses on the purposes and internal management of particular institutions. By synthesizing a wealth of new material into a comprehensive framework, Oliver's seminal study lays the groundwork for future students and scholars of Canadian history, criminology, and sociology.