United States Historical Geography
Because counties were often divided and their names and boundaries changed, you may need to determine previous boundaries and jurisdictions to locate your ancestors' records. A county history is the best source of information about a county's origin. Other sources that can help you determine the origin of a county are:
Kane, Joseph Nathan. The American Counties: Origins of Names, Dates of Creation and Organization, Area, Population, Historical Data, and Published Sources. Fourth Edition. Metuchen, New Jersey: Scarecrow Press, 1983. (FHL book 973 E2ka 1983.)
The Handy Book for Genealogists. Eighth Edition. Logan, Utah: Everton Publishers, 1991. (FHL book 973 D27e 1991.)
Other sources about boundary changes are found in the Place Search of the Family History Library Catalog under UNITED STATES - HISTORICAL GEOGRAPHY. The historical atlases described in the “Maps” section of this outline contain maps depicting county formations, migration and settlement patterns, military actions, ethnic distribution, religious trends, and population trends.