What's also super interesting is the fact that Southern American English, as a dialect, wasn't much spoken, if at all, before the Jim Crow Era. Everyone sort of talked like this and it's close to British in many ways. Colonial English.

The Southern Draw was a later invention as the South was trying to reestablish their identity after the crushing (to them) loss from the Civil War.

"Invention" is probably a poor word choice, as dialects like this come about by chance, isolation, and time.

Fascinating piece.