I remember reading something one time where the author said that if you could go back in time to England and the Colonies in the early 18th century, everybody would sound like “backwoods” Americans do now.
Not everybody; it would depend on the area. Settlers from the Scottish-English Borderlands, above Hadrian’s Wall, and from Northern Ireland would speak alike, regardless of where they had settled — some Scotch Irish came in through Georgia and SC, others went to areas in New England, for example. Settlers from southern England already had developed different usages. One area which remained isolated for a time was Manteo-Elizabeth City, NC, where traditional speakers pronounce “i” as “oi” or “oy”, as in “It’s hoy toid at Buxton” (”It’s high tide . . .”). Compare the strong “i” in Appalachian speech — it would be “high tide” here, and the same strong, clipped “i” sound would turn up in “light” and “might”, and so on.
My mother and other family were raised in a country town in Arkansas, quite frequently i hear words that make me think of early times. they say ye and arsh taters for potatoes etc. It is sad to think they will be gone soon and that type of speaking. as far as i know it.