From Peace's link above:

"Roll the Old Chariot Along" has direct connections with black folk music of the nineteenth century, appearing in most of the standard collections of spirituals (Dett, pp. 192-93; Fenner and Rathbun, pp. 106-7; Johnson, pp. 110-11). Sandburg published a variant (pp. 196-97), and it has also been noted by collectors of shanties, including Hugill (pp. 150-51) and Doerflinger (pp. 49-50, 357). A version of this was sent to Gordon by an Adventure reader (3758) and he collected another text in California (Cal. 243). There were many black sailors on the crews of nineteenth-century vessels. They brought with them traditions of work songs, and their songs, religious and secular, were usually rhythmic and thus suited for the many kinds of gang labor needed on the big sailing ships. Gordon devoted a chapter in Folk-Songs of America to "Negro work songs from Georgia" (pp. 13-19).

~S~