These immediately come to mind:
Livermush - my favorite breakfast food - served with eggs, naturally. Common in Piedmont North Carolina, Upstate South Carolina, and leaking over state lines a tad here and there. Made with pork liver, cornmeal, and spices. Makes a right nice sandwich, too.
Goetta - second cousin of the above. Common breakfast fare in the Cincinnati area. Uses oats instead of cornmeal, although I don't know what meat is used: probably pork.
Barbecued Mutton - ubiquitous in the area of Owensboro, Paducah, and Henderson, Kentucky and Evansville, Indiana. Served with a unique sauce called Black Dip. The favored side disk is Burgoo, a spicy stew similar to:
Brunswick Stew - a common side dish with barbecue in the South; may have originated in Brunswick County, Virginia, in North Carolina, or elsewhere. Consists shredded pork and chicken, plus a slew of vegetables (okra, corn, and tomatoes most usually).
Chicken Mull - a variation on chicken soup found in N/E Georgia and adjacent Upstate South Carolina. It's simply chicken stewed with a thickener and minimal spices. I refer to it as Pentecostal Penicillin because it is often served at Holiness Church homecomings up the road from here. In Oconee County, Georgia, the Disciples Of Christ churches (who are not Pentecostals) have it, too. So do several fire departments - at "fund raisin'" time!
Cornbread cooked on the grill: flat - the commonest variety around Nashville, Tennessee.
Mustard-based barbecue sauce - the preferred version in much of the central part of South Carolina, and - magically - it reappears with similar ubiquity in and around Columbus, Georgia. I prefer the brown mustard version, myself: more "oomph".
Cole slaw on a barbecue sandwich - what you'll get in Piedmont North Carolina unless you ask it off. Outlanders find this custom appalling, but I have grown to appreciate it. Which reminds me:
Red slaw - served in the Lexington, North Carolina area. Contains more vinegar than any self-respecting salad ever was dosed with.
Hush puppies - fried bits of seasoned corn meal that were tossed to the dogs while families were eating so as to quiet and pacify them until the meal was done.
Swamp cabbage - the growing heart of the palm tree, served in parts of rural Florida and greatly resembling regular old steamed cabbage.
Those are all that immediately come to mind. This spacer bar doesn't wanttowork.
Food For Thinkingly, Ort. Carlton in Southern Fried Athens, Georgia.