The wackipedia entry is fouled up, a frequent occurrence. "Wallis Willis" is a misunderstanding of the names Minerva Willis and Uncle Wallace. The story that the song was taught to the Fisk Singers in 1871 by these two former slaves of the Indian Territory was printed in a religious magazine, "The Presbyterian," in 1890. No verification is possible. Another story is that, at the funeral of an African Chief, he was seen to rise from the funeral canoe and enter a chariot; captured natives brought the song to America.