Some conflict on James C Cain, records show he married in ARk in 1870 in Hot Srping County. May be a misnamed soldier
The only person in the 11th to match Matthew Williams was CPL M. T. Williams of Co G. He was listed as absent sick when regiment was captured at Island 10.
All the others I checked in 2nd Bn and 3rd Inf and 6th Cav all are correct and actually clear up what happened to them.
Many Thanks