Actually, the " sleep tight " part, is 100s of years old, European in origin, and comes from the time when bedsprings were ropes, under the mattress, which loosened, with use. One had to continually have to retie the ropes, hence " sleep tight ", which gave better support. Bed bugs have been around forever and been a curse to sleepers. There is absolutely NOTHING particularly " SOUTHERN ", in that phrase. ;-)