I once saw a reenactor portraying George Washington who was speaking with what was essentially an English accent, because he believed that's how Washington spoke, However, an article published in the magazine Southern Partisan a few years ago argued that the Southern accent was up and running in the 1700's, and that Washington spoke with a drawl, y'all.
I too have read, maybe here on FR that Southern U.S. English is closer to what was spoken in say, the 1700s than modern Englishmen speak.
Of course there are many variations in different parts of the South. I recall a girl from Chester, South Carolina whose drawl was so thick I had real trouble understanding her. It didn’t matter because she was so pretty that I could have just stood there watching her and been happy.