County Boundaries of Selected United States Territories/States, 1790-1980

This cartographic database was created at the University ofWisconsin-Madison Cartographic Laboratory in conjunction with theNewberry Library and the National Endowment for the Humanities. Thecollection makes it possible to plot any or all of theterritorial/state and county boundaries in the region covered by thestates of North and South Dakota, Minnesota, Iowa, Missouri,Wisconsin, Illinois, Michigan, Indiana, Ohio, Pennsylvania, NewJersey, Maryland, and Delaware. The data collection also contains thecounty names, the names and locations of the corresponding capitalsand county seats, and information on the shoreline along the GreatLakes and the Atlantic Ocean. All changes in lines, locations, andnames are dated to the day according to their legally effectivedates. The data collection consists of 38 data files. Part 1 containsall of the cartesian coordinates (in digitizer units) required todefine the historical county boundaries for those 14 states. Part 2contains the "control" needed to convert digitizer units into latitudeand longitude. The remaining 36 files contain all of the descriptiveinformation needed to build the appropriate cartographic base for anygiven date.