Is the Midwest a vernacular region?

Vernacular, also called a dialect, refers to regional variations of spoken language. The US has several: Eastern New England English with its iconic non-rhoticity (dropping the "r"s); the distinctive Southern Drawl with vowel-shifting from pin and pen and fronting (moving vowels toward the front of the mouth, for example making cot sound like kit):; Midland, found mostly between the Appalachians and Rocky Mountains with the cot-caught merger (cot and caught sound the same to them); and General American, spoken mostly around major transportation cities with few distinctive features besides r-lessness on word and morpheme-final r's