Yes, it is possible that he was at Florence SC prison. When Sherman captured Atlanta it was feared that he would next go to Andersonville Prison and release the prisoners. (about 33,000 men) The prisoners (who were ambulatory) were told they were being released/exchanged (beginning in Sept 1864) but were actually taken to several smaller prisons that would be less attractive to free. These were Florence, Charleston and Columbia in South Carolina plus Savannah, Blackshear, Millen, and Thomasville in Georgia. Exchanges began again about two months later. Since he was at Florence he was most likely exchanged through Charleston, SC. As to Co E not being at Andersonville, on the death list of soldiers from TN I see J Brown, M A Baker, N. P. Poster, J. F. Ralph, R. Richardson, J Smith, etc all of whom were in Co E 13th/14th.