The families of Patrick Hagan, Andrew Hagan and Alexander Hagan are listed on the 1790 U.S. Census for Frederick County, Maryland. I did not find these families in the 1800 U.S. Census for Frederick County. Can someone suggest why these three families left Frederick County (if they actually did leave) and where they could have gone? I have thought they got caught up in a county line shift by I have no way of verifying this so I don't know what other county to go to to look for them. Any help appreciated. I am interested in the family of Alexander Hagan but believe all three are related.