The Valley of the Shadow of Death by Roger Fenton (1855)
This is fascinating on several levels. First, there is a lot of discussion about the circumstances of the Sebastopol siege. Second, the photos themselves are impressive: those spent cannon balls littering the ground like rocks create, at least for me, a sense of tremendous danger. Finally, the guy who wrote this piece is a pretty good empirical historian and raises interesting questions about the circumstances of the photos and about historiography generally. Also, Susan Sontag comes out of it looking like a dope.