He went to the war early with his Confederate master as his body guard / servant.

He reportedly assisted this east Tennessee Unionist in escaping from prison in Atlanta late in the war :

http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=clift&GSfn=william&GSbyrel=all&GSdyrel=all&GSst=45&GScntry=4&GSob=n&GRid=146716593&df=all&

Don't know if he could be rightly called a "Black Confederate." Sounds to me he did what he had to do to survive. Wearing a Confederate shell jacket wouldn't make him a Confederate at heart.