Goes to prove you can't assume anything in this business. I had no tombstone date of death, and no easy access to CSR for Mississippi units, so I took the date of death from the family genealogy site without checking. I "knew" he didn't get killed or mortally wounded at Fredericksburg, and just assumed it was either Sailor's Creek or Petersburg. Actually, since the Federals didn't arrive at Farmville until the 7th, and if the date of capture is correct - an perhaps a big if -- he would probably have gone up at Sailor's Creek, but there were a myriad of little engagements elsewhere during the day. What brigade was the 18 MISS in?
Farmville was full of hospitals, and, again assuming that he did not get captured unitl April 7, he could have been a patient in one of those. Union forces did not actually get into town until mid-Afternoon on April 7. I am thinking that men the Federals captured at Farmville were not sent back to the rear for transfer to permanent prisoner of war camps, and were paroled at Farmville between 11 and 19 April.
Since some of you fellows have access to Mississippi rosters, does it readily appear that he had a cousin, brother, etc. in the 18 MISS? Also, do you have a precise date of transfer?
Given his place of death, I suspect that erosion have taken his actual grave site into the Potomac/Chesapeake Bay.