Journal article: There is little doubt that both urbanization and industrialization changed the way people live and interact. However, even though family structure has long been considered as the best indicator of the changes induced, little is known, empirically, about its evolution. We take advantage of a large dataset of matched censuses in a fast industrializing city to investigate how families function in a new environment. We show that family formation confronted two structural forces: the sheer numbers of migrants and the company that dominated the labor market. The company tried to promote a new family model by allowing only some kinds of migrants, selected through housing and labor, to settle in the city. Many aspects of their lives were thus constrained by the firm's paternalistic organization. This process did not occur without resistance but it contributed to the integration of migrants in the city of Le Creusot.