Great photo. I've seen it before but not to this detail. Colorizing it really brings out the tiny tidbits here and there. What first struck me was that all their uniforms are different, with regular shirts underneath. The soldiers of the 1860's didn't get G.I. (government issued) clothing. They each had uniforms tailored by some civilian suit maker. Interesting that their boots look the same though. Of course a daily shave was most likely out of the question. I shave with a straight razor, but have hard enough time keeping a good sharp, stropped razor and can't imagine doing it in the bush! One soldier is sitting on what looks like a suitcase. Of course offices didn't carry a pack on his back, to demeaning. The tent behind them probably leaked like a sieve. No water proof materials like we have today.
What I really find interesting about the day was how they kept their pipes lit. I doubt there were any Zippo's about and matches were at a premium. When I'm out on the lake or in the woods, I go through enough matches to make a small tree! When I was a kid and camping with my grandfather, he used to take a hot ember from the fire and put it atop his tobacco. It not only kept his pipe lit for a while, it added it's own flavor. I've tried it myself... Try it sometime, it's very pleasing. (with a hard wood fire, not pine)...