The IPUMS National Historical Geographic Information System (NHGIS) provides free online access to summary statistics and GIS files for U.S. censuses and other nationwide surveys from 1790 through the present.

Through the NHGIS Data Finder, users may:

  • Filter and sort through thousands of available tables and GIS files
  • Select and download multiple tables and boundary files, for different geographic levels and from different years, all in one request 

NHGIS does not provide tools for data analysis, mapping, or reporting. Rather, NHGIS supplies data files designed for use in spreadsheet applications (e.g., Microsoft Excel), statistical software (e.g., R, Stata, SPSS, SAS), or GIS applications (e.g., Esri ArcGIS, QGIS).

Most NHGIS data files cover all areas in the United States. Data files for census blocks and block groups are available for individual states.

NHGIS is one of several IPUMS data integration projects housed with the Minnesota Population Center at the Institute for Social Research & Data Innovation at the University of Minnesota. The NHGIS project is funded by grants from the National Science Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

NHGIS highlights...

GIS files

  • County and state boundaries since 1790
  • Census tract boundaries since 1910
  • Metropolitan area boundaries since 1950
  • Block, place, and county subdivision boundaries since 1980
  • Boundaries for all standard census reporting areas since 1990
  • Place points, 1900-2015
  • Centers of population for states, counties, tracts, and block groups, 2000, 2010, & 2020
  • SABINS school attendance areas (2009-10, 2010-11, & 2011-12 school years)

Summary tables

  • Statistics from all decennial censuses and the American Community Survey
    • County and state tables since 1790
    • Census tract tables since 1910
    • Tables for all original census summary levels, down to census blocks, since 1970
  • County Business Patterns data (annual, 1970-2002)
  • Vital statistics: births & deaths (1915-2007), marriages & divorces (1867-2010)
  • Agricultural census data (1840-1950)
  • Religious bodies data (1850-1952)
  • Manufacturing census data (1840-1940)
  • 2010 Census data for SABINS school attendance areas
  • Annual census tract-level population estimates broken down by age, sex, and race (2000-2019)

Time series tables

  • Comparable statistics from multiple censuses and the American Community Survey linked together with standardized categories and codes across time
  • Two types of geographic integration:
    • Nominally integrated tables link geographic units across time according to their names and codes
    • Geographically standardized tables provide data from multiple times for a single census's units
  • More information available here

Supplemental data

API and R tools

  • The IPUMS API (Application Programming Interface) supports general programmatic access to NHGIS data and metadata
  • The ipumsr package for the R software environment provides an R-based interface to IPUMS, including NHGIS data and metadata
    • For a primer on accessing NHGIS in R, see this blog post