The persistence of certain migratory movements has engendered a growing interest in their historical process. In the case of Mexico City, some recent studies have called attention to the existence of structures and historical trends which help explain contemporary migration (Bataillon, 1972).

A study of the history of migrations makes possible precise observations on the mass population movements produced by great social changes. These changes, in turn, can be studied through an analysis of their effects. Historical analysis will certainly focus on migration as a phenomenon that affects social groups, because the documents—generally indirect—that record these movements throw more light on their causes than on individual motivations. This paper only points to some ways in which these movements might be analyzed, using as sources the municipal padrones (population registers) and censuses of the nineteenth century, which include information on places of origin. (A complete list of the padrones of Mexico City in the nineteenth century is given in Aguirre and Sánchez de Tagle, 1972.)