Interesting question to explore. In 1966, Pete and Toshni Seeger and Bruce Jackson produced a half-hour film titled Afro-American Work Songs in a Texas Prison (click). In 1956, Pete and Toshi did a Folkways album titled Negro Prison Camp Worksongs.

Also take a look at the Website titled 13 Great Prison Songs You Must Hear (click).
I see that the State of Mississippi (click) still has inmate work crews, and I'm sure many other southern states do.
Here's a Wikipedia article (click) on prison labor in the U.S.
I wonder if it's changed laws or alterations in work conditions that made prison work songs disappear.

-Joe-