census records and county boundary changes

Census Records and County Boundary Changes

Editor’s note: The following post on the importance of knowing the county in order to properly utilize census records, and how shifting boundaries can affect that search, is written by author William Dollarhide. An excellent source that can be used to visualize the county boundaries for every county in the U.S. and for each census year is the book by William Thorndale and William Dollarhide, Map Guide to the U.S. Federal Censuses, 1790-1920. This book has 393 maps showing each applicable census year and all county boundary changes from 1790 to 1920. Each map shows both the old boundaries and the modern boundaries for each state and census year, so a comparison can be made. 

Census Records and County Boundary Changes

All censuses taken since 1790 are tabulated and organized by the counties within each state or territory. By federal precedence, the county is the basic unit of jurisdiction for census demographics. Alaska is the only state without counties; therefore, judicial districts are used as jurisdictions for the censuses taken there. In Louisiana, the term “parish” is used in the same way as “county” in other states. Even in the New England states–where a town may have more importance than a county as a genealogical resource–censuses are organized by county.

Interestingly, Connecticut abolished county government in 1960. All county functions were taken over by the towns or by the state, except that the county boundaries were retained expressly for the purpose of taking a census and certain other statistical studies based on a county, rather than town boundaries. Continue reading…