There are some significant migration patterns that are different from the norm: most move west and slightly north or south depending the flow of the mountains and rivers from the point of origin. Geography may require that the travelers go out of their way along the trail. The general movement is still westerly with a north or south reading.
Virginia Tidewater Migrations. Most genealogical textbooks and migration studies warn the genealogist against linking a Valley of Virginia family with one of the same name from the Tidewater or Eastern Shore area of Virginia. And while there is good reason to move with caution, making careful analysis of the evidence you find, there is considerable migration from eastern Virginia into the Great Valley before the American Revolution. And a tidal wave of eastern families flowing into the western valleys after the war. See Alan Kulikoff, Tobacco and Slaves: The Development of Southern Cultures in the Chesapeake, 1680-1800. (Chapel Hill NC: University of North Carolina Press, 1986.) Using Revolutionary War muster rolls and original pension applications to track migrating Virginia families, Kulikoff maps their migrations into central and western Virginia–like river flowing into and through the mountains seeking new lands–
Migration within the Virginia tidewater counties, into the piedmont lands on the east side of the mountains, into the Southside where Pittsylvania county and its neighbors doubled in population, and into Augusta and the Shenandoah Valley through regular gaps in the mountians.
Here the Virginia-born population intermingled and intermarried with settlers directly from the British Isles and Europe (21%), from other parts of the Chesapeake (38%), and from Pennsylvania and New Jersey and Delaware and New York and Connecticut (17%).
Watch for these “hidden” eastern Virginians. They often carry the same surnames as foreign settlers. Your favorite Virginia genealogist, Arlene Eakle http://www.arleneeakle.com
PS More unusual migrations coming. Stay tuned.
PPS I plan to sneak into Virginia on my coming trip to OH, KY/TN, NY, and RI. Do you need research? Email me.