I don't know why but this topic is so interesting to me!! Whoever mentioned the thing about Country also being Country Western slipped my mind- good point!
I think it's interesting too. I mean, I grew up in San Jose CA, and there were always "cowboys" around...even with "southern" accents. Now once I moved to SC and started learning the different ways of speaking, i realized that the CA people were likely transplants, or grown children of transplants, from Texas and Oklahoma who had stuck with the accent, fashion sense (hats, boots, etc), and attitude. And music.
To me country western isn't southern, it's ranchers, farmers, etc etc, and there's a ton of that in the West.
As for other areas...isn't Keith Urban from Australia? And Shania Twain is Canadian, right?
And I'm sure that quite a lot of country music sounds like traditional Irish music, and then you could compare line dancing to Irish dancing in a way... I was at a "disco" in the west of Ireland in the 90s, and even though it was euro/techno mainly, the attitude of the dancing felt not very different from the clubs in Spartanburg, even though the music wasn't the same.
(then again, I can also hear the similarities between a Southern accent and a British one, so I'm either onto something or have lost my marbles)