Have to think on that one a little.
Ok. I'm done.
As I understand it, Appalachian really is Elizabethan English (or closer to it than our standard English of today), and the English of that era sounded more like our "hillbillies" than like contemporary English.
The same goes for "Black English." In fact, some factors (such as the use of the infinitive form of "to be" as a finite form) are common to both.