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"The Atlas presents in maps and text complete data about the creation and all subsequent changes (dated to the day) in the size, shape, and location of every county in the fifty United States and the District of Columbia. It also includes non-county areas, unsuccessful authorizations for new counties, changes in county names and organization, and the temporary attachments of non-county areas and unorganized counties to fully functioning counties. The principal sources for these data are the most authoritative available: the session laws of the colonies, territories, and states that created and changed the counties"--About the project.
Includes downloadable historical state and county shapelines for use with GIS programs. Zipped files include maps, database, and supplemental texts. Includes text, interactive maps and indexes.Includes bibliographical references. (OCLC)
"The Atlas of Historical County Boundaries project was successfully completed in June 2010. No further updates from the project are anticipated." (OCLC)