IPUMS Ancestry Full Count Data: Version 4.0

IPUMS USA makes freely available to researchers worldwide full count U.S. Census microdata through 1950. This dataset includes over 780 million individual-level (1850-1950) and 7.5 million household-level records (1790-1840). The microdata represents the fruition of longstanding collaborations between IPUMS and the nation's two largest genealogical organizations —Ancestry.com and FamilySearch— to leverage genealogical data for scientific purposes. This microdata collection is possible due to the donations of an unprecedented scale of digitized census data by both Ancestry.com and FamilySearch. Person-level microdata are available from 1850-1950. Complete count data for 1790-1840 are available at the household-level. In contrast to the 1850-1950 U.S. censuses, the 1790-1840 historical censuses named only the head of the household and tallied household totals attached to that record. IPUMS is continually improving the quality of these datasets by removing duplicate records, improving identification of household groups, applying numeric codes to the transcribed responses, etc. These improvements to the underlying data are periodically released via IPUMS USA. Updates since Version 3.0 include improvements to data from 1850-1880 released in October 2023, and the preliminary release of the 1950 data in January 2024 (see more at https://usa.ipums.org/usa/full_count.shtm ). The variable VERSIONHIST identifies the public-release version of a dataset. Researchers can merge data between versions of the dataset using HISTID to link individual cases across versions, capturing any updates, corrections, or improvements that may have been applied to the data. All data are coded and can be downloaded via the IPUMS USA extract system. Restricted versions of these datasets are also available.