An important element of our genealogical research is the use of maps. Often we forget to look at maps in the time periods that our ancestors lived or migrated to a particular area. Over time the landscape as it relates to maps has changed dramatically.
Here in Northwest Ohio up until the 1840's the rest of the states was very well developed with county lines and roads. Northwest Ohio was just a blank space on the early maps. A big reason for this was the existence of the Black Swamp. It provided a natrual barrier to migration through the area to both the West and North. When the German population entered the area and drained the swamp it allowed for better roads and more people to migrate to the area. Not to mention some of the best farm land in the world.
Pay attention to maps. Easy explanations can be resolved for difficult brickwalls by looking at a map for the time period our ancestors were living.