The map is atrocious.. Too much detail at that scale!! And I think I might've heard of the existence of an Appalachian category in Places like WV and parts of Tennessee. I'm a foreigner and even when I could barely tell the difference between dialects, I could very clearly see the huge difference between how people in WV and Eastern PA accents vs NJ and NY on the coast. Also, it seems odd that the "Canadian" dialect-s are so neatly aligned with the border!! I feel like people in much of Alberta speak some generic North American English and not a lot of "aboat". North of Ottawa in Quebec, Hull specifically, almost nobody speaks English!!! I lived there and everything was in French. Some people couldn't and did care to speak English even as a second language. The English that people speak in Quebec and particularly Montreal seems to also differ from the generic Canadian accent you know!