As far as AOII having a "southern" flavor, I think you also have to look at the alumnae base in the southern states. I can't speak for all of the southern states but I know that there are approximately 1200 AOII alumnae living in the Middle Tennessee area alone. That may explain why headquarters ultimately made its way to the Nashville area.
I can remember helping out at headquarters when it was a little cottage-like building in Green Hills. I think there is now an ATM machine where the old building used to be. Boy has AOII come a long way in the last 20 years!! All of us AOIIs from coast to coast and from Canada to the US have a lot to be proud of!!