Blueberries grow wild throughout Maine, wherever there are clearings in the woods. We have wild blueberry plants throughout our land in northern Maine. Although the bears and birds tend to get to the berries before I ever get a chance at them, I like bears and birds too, so I don't mind. I've cut a few small (30-50-foot) clearings in the woods so that there will be food for the wildlife, and one of the first things that will grow there is blueberries. I suppose the birds drop the seeds, spreading them. I've also planted a few domesticated blueberry plants, but they don't seem to compete well with the wild ones. Growing up in the UP of Michigan, we'd hit a few large wild blackberry patches whenever they were in season. One of them was so large and so thick that no one could get to the berries in the center because the blackberry thorns would bar access to the center, which was okay because there were plenty of berries along the edges. Raspberries were even more common there but not in concentrations, as was the case with the blackberries. We also had a large wild cranberry marsh near home, but it was so marshy that harvesting them by hand would have been a messy job that none of us wanted to undertake. Plus, cranberries don't taste good as they come off the plant. Here in Maine, where raspberries also grow wild, I have tried growing raspberries in the back of my yard, which seems like it would be good terrain for raspberries but the plants wouldn't survive the winter, so I gave up. The earlier posts in this thread provide a lot of information about them. Lingonberries are closely related to both cranberries and blueberries. When picked straight off the plant, they are not as sweet as blueberries but not as inedible as cranberries. I like the taste of lingonberries as they come, but my wife likes them only in jams or something after sugar is added. I don't think they grow anywhere other than in cold-weather areas, but they thrive in very cold weather, even when covered by deep snow for several months at a time. Since more than one variety is required in order to get good berry growth, I now have about five or six different varieties, each of which bears fruit at different times, usually one crop in the summer and another in the fall. There is good and bad in that. On the positive side, there are berries for me to pick and eat throughout the summer and fall, but on the negative side, there aren't enough of them at any given time to use in making jellies or jams. That's why I planted more along my side yard, but they haven't given me any fruit yet.
As far as I know, blackberries don't survive the winter here, but there are blueberries and lingonberries everywhere. I doubt they will live in the South as the chilling requirements are too great. You have so many things that we don't however. Enjoy what grows there.
We have blueberries here in Alabama and they grow just fine. When I lived in Idaho, there were huckleberries, which is like a blueberry, except they are smaller. In western Washington state, they have red huckleberries growing wild. They taste just like a regular huckleberry or blueberry, but they are bright red. We had thimbleberries there, too, and lots and lots of blackberries everywhere. I now have some Washington blackberries growing here, and they seem to love it because we get lots of rain here, too. I asked my niece on the west coast to send me some blackberry starts a few years ago, and she did, and those two tiny starts are now all along our side fence (no neighbors peeking through that fence !), and last year we transplanted starts out along the back fence. They are growing great out there and spreading along the fence. I looked at the lingonberry possibility, but I do not think they would grow here because they need the cold to thrive.
Once in a while I'll buy blackberries or blueberries in the grocery, but they are tasteless. They look plump and juicy but lack the flavor of wild. I haven't picked wild berries in a while. One year there was a bumper crop of blackberries in the woods where I once lived and I loaded up. Next year there was almost none in the same location. No idea why. Blueberry picking on the shore of the lake was a battle with mosquitoes unfortunately, but worth it..
My nephew has several acres of blueberries; he's a farmer in south GA. He grows them for the commercial market and I can have all I want but I have to drive 900 miles to get them. I have had lingonberry jelly but I've never seen an actual lingonberry.
We operated a small blueberry farm when we lived in Georgia, but the blueberries in the South are different from those in the North. Southern blueberries are generally the "Rabbiteye" type. They don't require the chill hours of other blueberries, and taste pretty much the same as the ones grown in the North, although they may have less sugar. There are two types of blueberries grown in the North that I know--the highbush "Jersey" type that are commercially grown, and the lowbush that are usually wild and grow everywhere here. We have both lingonberries and "real" cranberries on our property. The real cranberries are a nuisance to harvest without flooding, so lingonberries are the norm. A friend nearby has more blueberries and lingonberries, so my wife goes there to pick with her friend--"girl time" with armed protection against bears.