Wallace, I was privileged to be close to an elderly cousin of mine, who was born in 1903 and lived to be 97 (and was mentally clear as a bell and tough as nails to the very end). She was an educated lady who came from a good family in Virginia; if you are at all a student of the War you would recognize the family name instantly. She had been raised by her grandfather, who was a captain in the Eighth Virginia and survived Pickett’s Charge. Listening to her and to her older brother, I got a clear sense of the way people in NVA talked 150 years ago. It’s not very different at all from the way my surviving kin and I talk today. It’s not the rich Magnolia Mouth accent those from the Deep South have, though; more a question of rhythmicity, pacing, and a few different pronunciations.
Actors vary widely in their ability to mimic accents, and generally speaking, British, Irish, and Australian actors do far better jobs at getting the nuances of American speech right than native born Americans do when they try to sound like people from other U.S. regions. In "Cold Mountain", the least Southern accent was that of Renee Zellweger, a native of suburban Houston but a first generation American. In "Gangs of New York", Daniel Day Lewis, a Brit, did a far more convincing New York accent than Leonardo DiCaprio or Cameron Diaz did with their Irish accents.