Recent years have witnessed a growing interest in the social history of crime an-long a variety of disciplines. This book examines the rapid spread of uniformed police forces throughout late nineteenth-century urban America. It suggests that, initially, the new kind of police in industrial cities served primarily as agents of class control, dispensing and administering welfare services as an unintentioned consequence of their uniformed presence on the streets. This narrowed role hampered their ability to control crime, and, as modern social services developed and the police came increasingly to concentrate on crime control, they acquired a functional speciality at which they had never been particularly successful.