“Sometimes I Feel Like a Motherless Child” (or simply “Motherless Child”) is a traditional Negro spiritual. It dates back to the era of slavery in the United States when it was common practice to sell children of slaves away from their parents. An early performance of the song dates back to the 1870s by the Fisk Jubilee Singers. Like many traditional songs, it has many variations and has been recorded widely. (More from Wikipedia)
Since Richie Havens was about the only musician who had arrived at the 1969 Woodstock festival before the highways became hopelessly jammed, he played for hours. As he recalls (quoting from Wikipedia): “I’d already played every song I knew and I was stalling, asking for more guitar and mic, trying to think of something else to play – and then it just came to me . . . The establishment was foolish enough to give us all this freedom and we used it in every way we could.”
After a remarkably quick guitar tuning, Richie Havens then improvised a song called “Freedom” that was based on the Negro spiritual “Sometimes I Feel Like a Motherless Child”. It was this performance that made it into the Woodstock movie. Bob Dylan has incorporated “Motherless Child” into his songs; Wikipedia lists dozens of others who have also recorded the song in one form or another.