According to Wikipedia, “Swing Low Sweet Chariot, a old African American spiritual was first written by Wallis Willis, a Choctaw freedman in the old Indian Territory, sometime before 1862. He purportedly was inspired by the Red River, which reminded him of the Jordan River and of the Prophet Elijah’s being taken to heaven by a chariot (2 Kings 2:11). Many sources allege that the lyrics also referred to the Underground Railroad, the resistance movement that helped slaves escape from the South to the North and Canada.
Alexander Reid, a minister at a Choctaw boarding school, heard Willis singing these two songs and transcribed the words and melodies. He sent the music to the Jubilee Singers of Fisk University in Nashville, Tennessee. The Jubilee Singers popularized the songs during a tour of the United States and Europe.”
The song enjoyed a resurgence during the 1960s Civil Rights struggle and the folk revival. Perhaps the most famous performance was that by Joan Baez during the legendary 1969 Woodstock festival.”