Settlement and the intergenerational dispersion of kin as a spatial process in the nineteenth century US

Abstract

This study examines how families dispersed or remained clustered across three generations during the nineteenth-century American settlement process. While kin networks are known to influence migration decisions, economic outcomes, and reproductive behavior, most historical studies rely on snapshots of co-residence or proximity within a single generation. We extend this research by introducing a new methodological framework, the Intergenerational Symmetry Index, which takes the form of two measures, Stayer Symmetry and Migrant Symmetry, that capture kin retention and attraction across multiple generations using population-scale genealogical data. These measures are built from family-weighted and gendered lineal paths that trace grandparent (G1), parent (G2), and grandchild (G3) birthplaces to assess how rooted or dispersed family lines become over time and space. We apply these measures to eight grandparent (G1) birth cohorts that range between 1785 and 1866 across the US. Our results reveal a westward-shifting generational pattern of kin cohesion and dispersion during the settlement process, gradually giving way to more neutral patterns of dispersion as areas matured. Despite data limitations, including underrepresentation of women and non-white individuals in genealogical sources, our method captures consistent intergenerational patterns and confirms that family-based migration was a key feature of nineteenth-century US settlement. Our findings support and extend classic theories of demographic change, including Turner’s regional settlement stages, Easterlin’s fertility-inheritance dynamics, and Zelinsky’s mobility transition. They also underscore the importance of considering kinship, not just individuals, as a unit of spatial analysis. Our multigenerational approach reveals spatial processes invisible in census-based migration measures and, as genealogical datasets expand, offers a path for integrating family history with broader questions of migration, settlement, and demographic change.