One never knows.
All my life I have corrected my mother's word for 'hair.' She pronounces it as 'haar' and I always thought it was southern slang. During all this anthropology/archaeology learning I've done over the last few years I've learned that the Old English and Old High German word for hair is HAAR! I don't correct her anymore, lol. (Both sides of my family have English backgrounds)
I believe there are many 'southern' accents. Furthermore, I believe they are descended from the various people of different ethnicity that originally settled the various regions. Probably the most manufactured American accent is the standard TV news accent. My ears began to open when a Carolinian gal complained how I spoke in diphthongs all the time as do all Yankees. It seems Yankees can't make a simple vowel sound, they always make it like two vowels together. All the time I thought she had a drawl when it is the other way around.