In 1961 Sonny Boy Williams recorded the 1st commercial version for Chess Records and at the time Sonny was credited along with Elmore for writing the song.
The song was then reworked and recorded by Sonny Boy Williams in 1963 and the Allman Brothers in 1972. To make matters more interesting there are two known Sonny Boy Williams, as well Marshall Sheron was a record engineer who may not have been involved in the writting instead being an engineer often gave someone the opportunity to be included in writing credits for future royalty payments.