I recall a book called "Covered Wagon Geologist", set when exploration in Texas and Oklahoma was literally frontier stuff. It recounted people singing, I don't recall if it was on the trail or in a camp, and gave a few verses of a song I recognized as "The Liar" and is in the DT as "Ten Thousand Years Ago".

In the boomtown Houston I knew 80 years later, folk music was a complete nonentity. Glad times have changed again!