This presentation provides an overview of the Atlas of Historical County Boundaries (AHCB), a scholarly resource produced by the Newberry Library that tracks the historical evolution of U.S. political boundaries. It explains that understanding past state, county, and local boundary changes is essential for locating accurate genealogical records tied to specific historical locations. The slides demonstrate how researchers can navigate interactive timeline maps, inspect boundary change metadata derived from official session laws, and download GIS or KMZ spatial data for mapping applications like Google Earth. Overall, the presentation highlights how leveraging these historical boundary datasets enhances location-based family history research.
