However, when I look up any Andersonville records, his name does not appear. So, I've tried to figure out what happened to him from May 5th on. I found a NY Times Archive article listing him as being in the Locust Grove "Hospital" as of 15 Jun 1864. I sent my question to NARA and received surprising info. They couldn't find any records of him being at Andersonville. Instead, in his regiment's (146th NY) papers, they found a deposition taken of an orderly sergeant in his company (H). He was also a prisoner at Andersonville and stated that he had indeed seen my gggrandfather there and was "well acquainted" with him. He said "he saw him on the 11th day of September 1864 at Andersonville in a dying condition, at that time, he did not think he would live 24 hours. A prisoner in co F 146th Reg (NY) ........ (can't read) told me said Penner died ...... 12th day of September A.D. 1864." This deposition was accepted only after what we would call today a "full background check" of the sergeant. On his word, my gggrandmother got a pension for herself and their seven children.
Anyway, before I got this recent response from NARA, I was trying to find the course of events from when a Union soldier was taken prisoner, transported and
"checked in" a Confederate prison camp. I've found most luck w diaries, journals, letters or books by POWs that have been put online. Regarding Andersonville, after the prisoners were "checked in", they were organized into Detachments of 270, Squads of 90 aand Mess's of 30 for the purpose of receiving food rations.
I still haven't found the grave, but think he might be one of ten "unknowns" buried at Andersonville.