All persons are granted a limited license to use data and documentation from IPUMS NHGIS, subject to the following conditions:
- Redistribution: You will not redistribute the data without permission.
You may publish a subset of the data to meet journal requirements for accessing data related to a particular publication. Contact us for permission for any other redistribution; we will consider requests for free and commercial redistribution.
- Citation: You will cite NHGIS appropriately.
For all standard NHGIS data (accessed through the Data Finder or API) and for most supplemental NHGIS datasets, publications and research reports should include the following citation:
Jonathan Schroeder, David Van Riper, Steven Manson, Grace Cooper, Zachary Krause, Tracy Kugler, Tsu Zhu, and Steven Ruggles. IPUMS National Historical Geographic Information System: Version 21.0 [dataset]. Minneapolis, MN: IPUMS. 2026. http://doi.org/10.18128/D050.V21.0
A few of the supplemental datasets distributed through NHGIS are packaged as distinct products with unique recommended citations and digital object identifiers (DOIs). We list these sub-collections with alternative citations at the bottom of this page.
For policy briefs, online resources, or articles in the popular press, we recommend that you cite the use of NHGIS data as follows:
IPUMS NHGIS, University of Minnesota, www.nhgis.org
These terms of use are a legally binding agreement. You can use the data only in accordance with these terms, and any other use is a violation of the agreement. Violations may result in revocation of the agreement and prohibition from using other IPUMS data. If IPUMS or our partners are harmed from your violation, you are responsible for all damages, including reasonable attorney’s fees and expenses.
In addition, we request that users provide us with the title and full citation for any publications, research reports, or educational materials making use of the data or documentation. Please add citations to the IPUMS bibliography.
For information about previous versions of NHGIS, including past DOIs and recommended citations, see the links to past versions through the IPUMS NHGIS Project Description.
For information about changes to NHGIS data and site features over time, see the Revision History.
Citations for Supplemental Datasets
Publications and research reports that use any of these supplemental NHGIS datasets should cite them as indicated below:
- Small-Area Summaries of the Historical Built Environment: Berg, A. K., Leyk, S., Noi, E., Ahn, Y., Uhl, J. H., Ren, Y., Davydzenka, T., Schroeder, J., Van Riper, D. Small-Area Summaries of the Historical Built Environment from HISDAC-US: Version 1.0 [dataset]. IPUMS National Historical Geographic Information System. Minneapolis, MN: IPUMS. 2026. https://doi.org/10.18128/D051.V1
- Privacy-Protected 2010 Census Demonstration Data: David Van Riper, Tracy Kugler, and Jonathan Schroeder. IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data, version YYYYMMDD [Database]. Minneapolis, MN: IPUMS. 2020. (Replace "YYYYMMDD" with the specific data release vintage, corresponding to the PPMF version published by the Census Bureau.)