A dialect is a regional variation of a language distinguished by distinctive vocabulary, spelling, and pronunciation. Dialects are regional variations of languages. American and British dialects differ in vocabulary, spelling, and pronunciation.
Northern dialects in the US were established and inhabited almost entirely by settlers from England. Two-thirds of the New England colonists were Puritans from East Anglia in southeastern England, and only a few came from north of England. About half of southern came from southeast England, although they represented a diversity of social-class backgrounds, including deported prisoners, indentured servants, and political and religious refugees.
map of american english dialects
A tour of the British Isles in accents