I've lived in Florida, Montana, upstate New York (Adirondacks) and currently in Tennessee. When I lived in Florida, It was and still is Coach. On my last few visits to see family, I noticed mostly Coach, some Louis Vuitton and some Vera Bradley. In Montana, Dooney and Bourke is popular, along with some Coach (this may have to do with the fact there is no Coach store/outlet in Montana). I can remember being in Dillard's in Billings and seeing teenage girls drooling over a couple of Dooney's and completely ignoring the huge Coach display nearby. In upstate New York, it was Coach everywhere. I suspect because resort town Lake George had a Coach outlet. Here in TN, there's lots of Coach, lots of Louis Vuitton (there is an LV boutique in Nashville about forty minutes away), Vera Bradley and a bit of Dooney and Bourke.
I think it is interesting to see what handbag brands are popular in different parts of the U.S. My husband travels a lot for his job, and when I get to go with him, I will "purse watch" to see what is popular, LOL.