Time period of content

1960

Publication date

2013

Abstract

This boundary file contains historic census tract boundaries for which the U.S. Census Bureau tabulated data and was produced by the Minnesota Population Center as part of the National Historical Geographic Information System (NHGIS) project. The NHGIS is an National Science Foundation-sponsored project (Grant No. BCS0094908) to create a digital spatial-temporal database of all available historical US aggregate census materials. The available shapefiles on the NHGIS site represent version 1.0 of historical US census tract boundary files for the 1910-2000 censuses. These electronic census tract boundary files were created by referencing publicly available, printed U.S. Census Bureau maps and considerable care was taken during their production. TIGER/Line spatial features that corresponded to boundaries on these maps were used to construct proper historic boundaries. When a TIGER/Line features was not available, we digitized the historic boundary from a geo-referenced, scanned census map. The boundary files have been checked against currently available historical census aggregate data.

Purpose

This shapefile represents the output from NSF Grant BCS0648045. This grant supports the re-alignment, or conflation, of the historical census tract and county boundaries in NHGIS with the Census Bureau's more accurate TIGER features, created through the MAF/TIGER Accuracy Improvement Project. This project greatly improved the spatial accuracy of the TIGER features, but at the cost of no longer aligning with the NHGIS boundaries. We used ESEA's MapMerger extension to ArcGIS to align the historical census tract and county boundaries with features from the 2008 TIGER/Line shapefiles. These data are based upon work supported by the National Science Foundation under Grant No. BCS0094908 - in infrastructure grant provided for the social sciences. Its purpose is twofold. First, the NHGIS created and freely distributes a database incorporating all available aggregate census information for the United States between 1790 and 2000. The database contains information for a wide variety of statistical (blocks, block groups, census tracts, metropolitan statistical areas) and administrative units (places, minor civil divisions, counties, states). Second, the NHGIS produced and freely distributes boundary files for small areas (census tracts and counties) in the United States. Boundary files for tracts are available for the 1910-2000 censuses, and boundary files for counties are available for the 1790-2000 censuses.

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Sources

Included data

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