Born out of the oral tradition of African music. Field hollers, or work songs, were performed by enslaved Africans working on plantations as a way of communication and for entertainment to combat the tedium of field work.
Enslaved Africans referred to the Big Dipper as the Drinking Gourd. It was supposedly used as a coded instruction to slaves to plan their escapes. Peg Leg Joe, who may or may not have been a real person and an operative of the Underground Railroad, has been credited with spreading the song to different plantations.
The music of the enslaved evolved to become America's music.