East coast, in contact with England, has North American English. Interior populated by different religions, developed generic linguistic pattern. Rhetoric labeled of North American speech supported by hiberno-English and Scottish English.
Children absorbing these accents Accents learned by imitation. Difference of vulnerability in different stages of life (in childhood we imitate parents' accent). Accent is developed socially (example Lancashire cotton mills).
Common American characterized by merger vowels. Southern accent British English and American Southern English, influence of French Huguenot. Miami accent (2nd and 3rd generation with English as the first language).