From my fiddle tune a day post: https://www.vithefiddler.com/shenandoah-fiddle-tune-a-day-day-61/
“Oh Shenandoah” (also called simply “Shenandoah”, or “Across the Wide Missouri”) is a traditional American folk song of uncertain origin, dating at least to the early 19th century. The song is number 324 in the Roud Folk Song Index, but is not listed amongst the Child Ballads. The lyrics may tell the story of a roving trader in love with the daughter of an Indian chief; in this interpretation, the rover tells the chief of his intent to take the girl with him far to the west, across the Missouri River. Other interpretations tell of a pioneer’s nostalgia for the Shenandoah River Valley in Virginia, or of a Confederate soldier in the American Civil War, dreaming of his country home in Virginia. The provenance of the song is unclear. The song is also associated with escaped slaves. They were said to sing the song in gratitude because the river allowed their scent to be lost. The Shenandoah area made many parts like wheels and seats for wagons going west. These parts were assembled in Conestoga Township, Lancaster County, Pennsylvania and settlers set out in Conestoga wagons down the Ohio River, on the Mississippi and west up the Missouri River. Lyrics were undoubtedly added by rivermen, settlers, and the millions who went west.