Lighter, the DT {Digital Tradition} indicates that this is a spiritual.

If you are asking who composed this particular spiritual, we'll never know. But I for one say thank you.

If you are asking who collected this spiritual and who published it, thus preserving it for "regular people" and for great artists like Nina Simone to sing, I don't know that either.

But I did find a couple of previous Mudcat threads on this song

thread.cfm?threadid=38494#541448
"Lyr Req: oh sinner man"

and

Lyr/Chords Req: Sinnerman
thread.cfm?threadid=17622#170625

You may want to check out the first thread that I referred to.
I just posted a link on it to a YouTube video clip {music only} of Bina Simone singing "Sinnerman". I also put lyrics to that song that I found online in that same post.

Best wishes,

Azizi