Good point. There would be aspects of what we now call a "Southern drawl" and of British English, but trying to get at the sound of it would be difficult. Chesapeake accents were quite different from what we now call a Southern accent.
Exactly. Virginia isn't Alabama. And it always amuses me when actors portraying Robert E. Lee always give him a Gulf Coast Deep South drawl.
The few times I have heard someone from Virginia, Maryland, or West Virginia, they have all seemed to have a very prominent "R," unlike the stereotypical Deep South dropped "R." The Upper South is rhotic, the Deep South is non-rhotic (except for American Blacks, who appear to be almost universally non-rhotic wherever they are).