These are a couple of photographs of Union naval activity on the Alabama River...one of the ships appears to be sternwheel tinclad.
http://louisdl.louislibraries.org/cdm4/document.php?CISOROOT=/LSU_MDP&CISOPTR=365&REC=7
http://louisdl.louislibraries.org/cdm4/document.php?CISOROOT=/LSU_MDP&CISOPTR=366&REC=8