The Atlas describes and maps every change in the boundaries of all United States counties from the early 1600s to 2000. In addition, the atlas compiles and maps all changes in colonial or territorial and state boundaries, including the evolution of the states, plus county name changes, unsuccessful proposed counties, and attachments of unorganized counties and non-county areas to operational counties. In most cases, a separate map is available for each different county configuration. view maps or Download Historical State and County Shapefiles. Zipped files include maps, database and supplemental texts