Why does it seem like all Evangelicals speak with a southern accent?

Wow!! I seriously thought I was the only one to notice that. I just thought I was weird or something. Now, I can see it's not just me. I don't know why every preacher needs to speak southerly. We have a great minister in the town 55 miles to the south of me. He is an older minister and I think he's the only one I know that DOESN'T talk southerly. But besides him, even as far north as I am, I hear it every week. We have evangelist come into the institution and preach to the inmates, and every single one of them preaches southerly. But when we talk to them, they talk without an accent. It's amazing, really. God Bless