I don't know what you mean by an expert. Do you mean someone with very extensive knowledge? If so, try describing exactly the type of information on Camp Sorghum you are seeking. I'll bet you receive 5 or 6 responses from some very knowledgeable people (i.e., researchers) here that collectively might give you just what you are looking for.
Not sure if this is of any interest but thought I would share
OUR ESCAPE FROM CAMP SORGHUM .
By Lieutenant Charles O . Hunt . CTOBER 6 , 1864 War papers, Read Before the Commandery of the State of Maine, Military Order of the Loyal Legion of the United States :