The IPUMS projects are undertaken at the Minnesota Population Center, an interdisciplinary research center at the University of Minnesota.
The IPUMS-USA samples draw on every surviving United States census from 1850 to 2000 (with the exception of the 1890 census, which was destroyed in a fire) and from the American Community Survey of 2000-2005. During certain years, IPUMS-USA also makes available over-samples of African-Americans, Alaskans, American Indians, Hawaiians, and Hispanics. The IPUMS provides consistent variable names, coding schemes, and documentation across all the samples, facilitating the analysis of long-term change.
The IPUMS-International samples currently include countries from Africa, Asia, Europe, and Latin America between 1960 and 2000. Ultimately, the IPUMS-International project will include hundreds of samples from more than 40 countries around the world. IPUMS-International converts census microdata for multiple countries into a consistent format, allowing for comparisons across countries and time periods. Special efforts are made to simplify use of the data while losing no meaningful information. Comprehensive documentation is provided in a coherent form to facilitate comparative analyses of social and economic change.
Additional projects currently underway at the Minnesota Population Center include: (1) the North Atlantic Population Project (NAPP), (2) the National Historical Geographic Information System (NHGIS), and (3) the Integrated Health Interview Series (IHIS).
The Journal of American History described the effort as "One of the great archival projects of the past two decades." The official motto of IPUMS is "use it for good, never for evil." All IPUMS data and documentation are available online free of charge.