Data Documentation

Tabular Data Sources

Documentation for the digital sources of NHGIS tabular data:

Time Series Tables

Time series tables link together comparable statistics from multiple censuses. The documentation describes how time series are constructed; summarizes which topics, years, and areas are covered; and provides a listing of all table sources and notes.

GIS Files

The GIS files are mainly based on the U.S. Census Bureau TIGER/Line files with additional editing and digitization to produce historical boundaries in accordance with several map sources.

Release Log

Two types of releases are documented: updates to the NHGIS website and updates to the NHGIS data (tabular or boundary data).

Supported By

Eunice Kennedy Shriver National Institute of Child Health and Human Development National Science Foundation University of Minnesota