The Inland North with the Northeast the most and the West the least. But I've lived my whole life in California, which was west last time I looked. However, I was born in Minnesota and grew up in a household of Minnesotans transplanted to California. Grandpa was Norwegian. Or as wikipedia said, "Minnewegian".
So I guess in California, full of immigrants from elsewhere, it's more a potpourri of accents than a distinct accent alone.
Artemis
