Genealogical Sources on the Internet provides a quick way to get to the information that you are looking for. Scroll down to the list of states. That will take you to GenWeb and other state historical resources. Don't overlook the mailing lists. Subscribing to the one for your target location can get you details about the area that will save you vast amounts of research time.
Historical maps are another resource, and fun, too.
Ones that show roads and trails from a time when travel options were limited are a wonderful clue to the movements of your forebears. Two such maps are US Scanned Map of 1834 and Exploration Map of 1850 . I discovered that cartographers are busy on the Web. In fact, I was overwhelmed. United States Atlas 1895 and The University of Texas at Austin's List of Historical Maps of the United States .