This dissertation examines the history of consent in the United States over the course of the late nineteenth and early twentieth centuries. It traces how, in the half century after the American Civil War, consent became more diffuse, capacious, and embodied. The dissertation offers a sustained study of consent across different facets of American life, spanning six decades of modern industrial transformation. It examines consent as a historically dynamic concept that traveled across time and social relationships, transforming in its scale and scope, its usage and effects. It follows consent’s journey outside of contractual relations, within various domains of social life—from sex to medicine to photography, and then back to politics, ever-present there but in relitigated forms. The dissertation illuminates how the body became the principal site of debate over the legal, moral, cultural, and epistemological boundaries of consent, shedding new light on the meaning of bodily freedom within the liberal social order in America. In the process, it uncovers a history of violence, inequality, and liberal democracy that tested how many bodies consent could bear.