Knowledge of the demography of multigenerational family ties is limited to the 20th and 21st centuries. Exploiting crowdsourced genealogies (the FamiLinx data), our research note empirically reconstructs the changing multigenerational family from pre-industrial colonial America (1700) up to the end of the gilded age (1910) in today’s United States in comparison with contemporaneous data from selected European regions. We estimate supply of and exposure to multigenerational kin measured by the number of, and years of life shared with, parents and grandparents. Multigenerational supply and exposure increased in the US and all European regions, but changes were modest compared to the surge that followed in the 20th century. Historically, the multigenerational family was consistently stronger in the US than in all European regions yet from 1850 onwards differences diminished. Our study documents, for the first time, the substantial cross-continental differences in the demographic-historical pathways leading up to the modern multigenerational family.