The infamous "n-word" epithet for Jim was apparently
used before Albert Bigelow Paine.  I found the phrase used in
a review of _Puddn'head Wilson_ from
_The Booklover's Magazine_
for February, 1904.  The review was written by T. M. Parrott.
        I've misplaced the original message, but I hope that this
helps whoever was asking about the origins of the term.

Donna Campbell