Given the paucity of information on historical kin relations, this study uses survey data in order to investigate how different family forms influenced the size and composition of social networks and the relationships among elderly siblings born in farming families between 1903 and 1937 in three regions of the Netherlands. In the area with stem families, impartible inheritance, and a custom of neighbor help, social networks are largest and contain the most siblings. Multilevel analyses show that even when controlling for other factors, this particular family form positively affects contact frequency in sibling relationships. Our results not only show the persistence of differential kinship values, but since respondents' networks were linked back to their families of socialization in the early twentieth century, findings also reflect regional disparities in kin relations in the past. © 2007 Sage Publications.