Thank you, this was informative.Because the spelling of many soldier letters is phonetic, they are often very hard to read & understand. I have found that even some of the most difficult to decipher come to life when you read them out loud. Accents & pronunciation reveal themselves.
Gullah & Geechee are still living languages on the Barrier Islands. They are an amalgam of West African dialects & English.
A chance encounter with the actor Michael York, of all people, greatly expanded my understanding of the origins of the Appalachian Mountain accent. Folks from deep hollows & coves still speak a form of Elisabeth English. Rather than the BBC standard we hear today, Shakesphere spoke with a hillbilly accent.
A folklorist, the late Charles Wolfe, was a friend of mine. He collected I don’t recall how many Elizabethan songs & poems from a couple who were in their 80’s. They had learned them as part of a family repertory.
In the upper Midwest, there are groups of people who still speak antique forms of German & Norwegian that CW era soldiers would have spoken. The same can be said of Native American speakers.
I am familiar with Cajun accents via the late Jimmy C.Newman & a Florida Panhandle family of Cajuns who are on the Nashville music ‘binis’. I am told that amalgamation of French, African & Native American languages is a hold over.
The “Southern accent” heard in TV & Movies is analogous to American’s attempting to speak BBC English. A good friend who grew up with a Coastal Carolina socially elite accent had a career as a stage & TV actor. New York, California & English directors insisted they knew what a Southern accent was & demanded that he assume the affected pseudo-accent they were familiar with.
My brother who lives in Maine assures me that Mainers have maintained their accents from of old.
So, to directly answer your question, linguists will, if given the chance, bend your ear endlessly about present day accents & where they came from.
One thing you may not have considered is that the white women of slaveholding families spoke like the slaves did. Makes sense, given their relative isolation. Elite slaveholding men affected an English upperclass accent, whatever that was in 1860. This is way outside my patch, but I have been told that echos of that divide still exist among some Coastal Carolina families. Scarlet O’Hara speech would have been filled with Africanisms as she would have dipped snuff & spit tobacco juice instead of the pretend British Southern accent of the movie Gone With the Wind.
Thank you for reminding people in the South that there are regional dialects "up north" too.Michigan's Upper Peninsula and the Yooper dialect which is heavily influenced by the Scandinavian languages.
Don't forget the true "yankee" accent, that of New England.
There are, of course, several different dialects within New England.
Even though I nor my parents had never been to New England, I had a Bostonian accent until about the 4th grade. My English teacher would keep me after school to coach me in proper pronunciation because some kids in my class would make fun of the way I talked. When JFK was elected to the presidency, my mom and grandmother would tell me that I used to talk just like him.