This essay examines the history of the prison since late the eighteenth century. Following a discussion of the origins of the reformative prison, the essay analyzes its global expansion as a tool for disciplining populations, expanding imperial control, and establishing national legitimacy. In particular, it emphasizes the dialectic between colonial and national projects and the multiple uses that the prison has come to play in states around the globe. From its origins as a local response to particular issues of crime and disruption, during the nineteenth century the prison became a sign of modernity itself. Its twentieth-century history, in the United States and across the globe, only tightened its relationship with systems of racial domination and the continuing legacy of colonial violence. The prison now marks the collapse of Enlightenment hopes for a more humane system of punishment.