For at least the 5th straight year, the Atlas of Historical County Boundaries, cited as being “simply the best way to understand how shifting county boundaries might have affected the whereabouts of your ancestors’ records,” has made Family Tree Magazine’s “101 Best Websites” for genealogists.
Why pay attention to boundary changes? As the website explains, “Few counties today have their original configurations. As the non-Indian population grew and spread across the continent, territories and states created new counties and changed those already in existence. The average number of changes in size, shape, or location per American county is between four and five; some counties were changed more than two dozen times. Most boundary changes were alterations of the lines between existing counties, not the results of creating new counties from old ones.”
With all the changes that occurred across time, it is possible that, although an ancestor lived on the same plot of land for many years, we may find records for him in several counties. For example, in 1845 Merrill, Wisconsin was part of Portage County; in 1850 it was located in Marathon County; and in 1875 Lincoln County had jurisdiction. In most cases, records remained with the jurisdiction in charge at the time of the event, but a careful examination of the records is always essential.