This website at the Newberry Library http://www.newberry.org/ahcbp/ was posted to the Vermont list but is of value in researching other states as well. Choose a year and see the county names and their boundaries. If your ancestor is found living in different counties with each succeeding census, it's possible he/she didn't move at all, just the name of the county changed. It's also helpful to see what the neighboring counties are. Perhaps your ancestor only had to travel a mile or two to visit relatives, depending on the nearness of the county line to their respective towns or property. Linda