Yes, that was it. I did a search on Glenn's ancestry before, as I usually do with celebs I'm a fan of, and it sent me here and I saw that page too.

But with Glenn's accent I was listening to videos of him talking again and taking into account about the Appalachian people moving to Detroit I can hear it in the way he pronounces certain words. So I do think he grew up around those accents too like most of us in the mid-west.