Old thread, but perhaps new info.
In 1911, the 10 volume Photographic History of the Civil War was published. William W. Silkworth recognized the men in the picture as his company, and wrote this letter to the editor.
"In looking the pictures over, you cannot appreciate or understand fully my amazement and joy in discovering that one was my old Company B, 170th Regt. N.Y. Vol. Why, I could scarcely believe my own eyes, so wonderful was it, that after forty-seven years, this picture should come to me. But there they were, some of them looking right at me, who had been dead for forty-six years- and there was no getting away from the picture.
Today I am a boy again, living once more with the boys, the old army life. There were about twenty-five of us, school friends, who enlisted together, at Greenpoint, Brooklyn.
There right in the front of the picture sits my brother playing cards (You will note that he is left-handed. We laid him away in front of Petersburg). With him is John Vandewater, Geo. Thomas and Wash. Keating. There is Charlie Thomas and all the rest as large as life. With the exception of two, I have not seen any of the boys for thirty years.
Some younger eyes then mine, say that they can see a figure in the background with a flag. If so, it must be me for I was Color Sergeant...