US regional accents and immigrant populations

I was thinking about regional accents in the united states and I wondered whether they might derive from a large but homogeneous group of immigrants settling in the area. I can think of at least one candidate for this type of thing. I know I heard something about linguistically isolated populations in the Appalacians preserving music and language elements from the time those communities originated. Anyone know if this sort of explanation applies to other accents?

Yes, it does. The southern accent is derived from common English accents, and Scottish/Irish. The Minnosota accent is the most obvious, being Norweigian.

Josh

New York City has a large, socially insular Italian-American population, the vast majority of which have roots in Southern Italy and Sicily.

Buffalo has a large, socially insular Italian-American population, the vast majority of which have roots in Southern Italy and Sicily.

Why is the New York City Italian-American accent so much different than the Buffalo Italian-American accent?

what about southeast michigan (lower peninsula)?

and yes, the lower peninsula and the upper peninsula have vastly different accents.

Northern Michigan University did a study a while back that showed Finnish significantly affected the way English is spoken in da U.P. Sorry, but I haven’t been able to find a cite for that. I happened across it during research a while back.
Say ya to da U.P., eh?

What bugs me a lot is this dopey impression some Americans have that we Canadians all say "aboot’. That mannerism is limited mostly to the people on the East Coast (Newfoundland in particular). Since the Canadian population is spread out over a huge area, comparable to the U.S., regional variation is a given. Specifically, an urban Montreal sophisticate like myself speaks standard and, ahem, flawless English.

So there, eh?