After the Civil War, the State of New York Intervened and created new mechanisms to manage New York City with sufficient authority, resources, and expert personnel. The decision to construct a comprehensive sewer system was a complex one that pitted individual liberty against the common good and political considerations against those of professional physicians and engineers. This history of policy formation is, then, a story of changing values and ideas that must be understood within the context of the social, economic, political, and intellectual milieu of the middle of the nineteenth century.