This book analyzes the human consequences of urbanization and geographical mobility for residents of a major city in the Ruhr Valley of Germany during the century-long transition from an agrarian order to the industrial era. By documenting the dynamism of Duisburg's population, the interdependence of urban and rural life, and the importance of households and social networks, it reshapes the conventional understanding of central European migration The unprecedented scope of this analysis of these social processes is made possible by a unique combination of detailed census manuscripts, vital records, police residency registers, and building permits that are unmatched by any other nineteenth-century European or North American city.