Navy General Order No. 65, issued June 19, 1863, includes a listing of the numbers assigned to the tinclads. This GO is shown on page 187, volume 25, of the ORN.
The list of the officers of the USS SPRINGFIELD, Mississippi Squadron, as of January 1, 1864, were:
Joseph Watson, acting master;
H.T. Keene, acting engisn;
Acting master's mates: S.H. Harbeson, James Cunningham, John Gregg and David Pullman;
R.L. McLean, acting first assistant engineer, and
Morris Van Fossen, acting third assistant engineer.
The Naval Historical Center web site also includes photographs of many of these tinclads. Unfortunately the USS SPRINGFIELD is not one of these, so your photo, or a reproduction, may be a welcome contribution to the collections of the NHC. It should also be quite possible to identify the rank and position of the officer shown in the photograph, through the identifying insignia include on cap badges, sleeve insignia, etc.