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IPUMS Linked Census Data

IPUMS disseminates full count census enumerations for ten census years from 1850 to 1950. These full count data, covering over 700 million individual records, are the fruit of collaboration between IPUMS and the world's two largest genealogical organizations — and FamilySearch — to leverage genealogical data for scientific purposes. Full count data have opened the possibility of automated record linkages across census years to construct millions of individual life histories and trace millions of families over multiple generations.

Multigenerational Longitudinal Panel

The IPUMS Multigenerational Longitudinal Panel project links individuals' records between censuses. The current MLP data consist of links across the censuses of 1850 through 1950. Linked individuals are assigned a unique identifier that is consistent across censuses. We also link information from the Social Security Administration Numident file to the twentieth-century censuses. We plan to build on this work in future releases. We expect that IPUMS MLP will eventually serve as a general framework that can incorporate records from a wide range of sources.

Next steps

We plan to integrate the newest 20 and 30-year, Social Security, and army enlistment crosswalks into the IPUMS dissemination system, where they can be more easily accessed. In achieving this integration, we will resolve contradictions between the links in the different crosswalks. The Social Security data, from which we often can infer women's maiden names, will allow us to improve and expand the female links in the system. We also intend to improve the flexibility of the extract system in the specification of linked datasets.

Project team

Steven Ruggles, Principal Investigator (MPI)
John Robert Warren, Principal Investigator (MPI)
Jonas Helgertz, Lead Research Scientist
Nesile Ozder, Senior Data Analyst
Catherine Fitch, Co-investigator
J. David Hacker, Co-investigator
Evan Roberts, Co-investigator
Matthew Sobek, Co-investigator
Matt A. Nelson, Research Scientist
Martha Bailey (University of California, Los Angeles), Consultant
Joseph Ferrie (Northwestern University), Consultant
Joseph Price (Brigham Young University), Consultant


IPUMS MLP is funded by the National Institute on Aging grant R01AG057679.

Contact us

For questions about IPUMS linked data, contact