Atlas of Historical County Boundaries

County boundaries have changed a lot during this nation's history. When searching for county-level records (birth, marriage, and death records) or when browsing census data, it's important to know which county your ancestor lived in. The Newberry has a great site that can help pinpoint what county your ancestor was living in during a specific period of time. The Atlas of Historical County Boundaries contains interactive maps and county histories and is a great resource for US genealogy research.