"Calvin Leavy (April 20, 1940 – June 6, 2010) was an African American soul blues and electric blues singer and guitarist. He had a hit single in 1970, when 'Cummins Prison Farm' peaked at number 40 on the US Billboard R&B chart, and stayed in the chart for five weeks. More locally, it was number one on the chart of the Memphis, Tennessee based radio station, WDIA."
"Later in his life, Leavy became the first person indicted under the 1988 Drug Kingpin Law, and he subsequently died in prison." (http://www.bluesprofiles.com/Bios/Calvin%20Leavy.html)
Two other versions of the song I like very much are those of Joe Simon and Snooks Eaglin.