County Boundaries of Selected United States Territories/States, 1790-1980 (ICPSR 9025)

Published: Jan 12, 2006

Principal Investigator(s):
John H. Long

Version V1

This cartographic database was created at the University of Wisconsin-Madison Cartographic Laboratory in conjunction with the Newberry Library and the National Endowment for the Humanities. The collection makes it possible to plot any or all of the territorial/state and county boundaries in the region covered by the states of North and South Dakota, Minnesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, Indiana, Ohio, Pennsylvania, New Jersey, Maryland, and Delaware. The data collection also contains the county names, the names and locations of the corresponding capitals and county seats, and information on the shoreline along the Great Lakes and the Atlantic Ocean. All changes in lines, locations, and names are dated to the day according to their legally effective dates. The data collection consists of 38 data files. Part 1 contains all of the cartesian coordinates (in digitizer units) required to define the historical county boundaries for those 14 states. Part 2 contains the "control" needed to convert digitizer units into latitude and longitude. The remaining 36 files contain all of the descriptive information needed to build the appropriate cartographic base for any given date.

Long, John H. County Boundaries of Selected United States Territories/States, 1790-1980. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2006-01-12.

Export Citation:

  • RIS (generic format for RefWorks, EndNote, etc.)
  • EndNote

National Endowment for the Humanities

1790 -- 1980

1975 -- 1981

United States Geological Survey maps

mapping data



2006-01-12 All files were removed from dataset 41 and flagged as study-level files, so that they will accompany all downloads.


  • Data in this collection are available only to users at ICPSR member institutions.

  • The citation of this study may have changed due to the new version control system that has been implemented.
ICPSR logo

This study is provided by ICPSR. ICPSR provides leadership and training in data access, curation, and methods of analysis for a diverse and expanding social science research community.