YES! Plat maps can be invaluable. My great finds were the Plat maps for Wm Penns "Manor of Maske" (land he apparently wanted as his own, but didn't end up with). This is the Gettysburg, PA area. Someone did a wonderful job plotting out all the old farms and putting names with all of the plots. I 'color coded' the names I was interested in and it helped a lot connecting people and families. Good luck. Sue