East Virginia doesn't refer to a state. It refers to eastern Virginia. Reflects migration patterns. By the early 1730s the eastern seaboard, in fact, nearly all the Atlantic coastline, was pretty well taken up by earlier and more wealthy folks. By at least 1730, immigrants arriving on what is now the USA east coast anywhere between Philadelphia and Charleston, SC quickly moved west and south.

The Great Wagon Road, in particular, was a major migratory path south and southwest from the eastern seaboard and the coastal and tidewater regions of Virginia, down into the 'back country' of the Carolinas and on into northwestern Georgia.