There is a lot in what Nicole Castle says. Going back over family records and Civil War correspondence, I find everything from very good to barely understandable writing. One member of my family tree who went from the farm in western NY to the California Gold fields was unable to read or write. He was a witness at a criminal trial and had to have his mark witnessed. Yet his speech was probably very close to that of his literate cousins, whose letters are quite well-written.

How do you accurately represent dialect in print? Even common dialectisms like heer'd looks odd, but it is as close as I can come in writing, without resorting to the odd symbols a philologist might use. American dialects have largely disappeared over the last 50-60 years. It is a mistake to deny that they ever existed.