You would think there would be alot of very good movies about the American Civil War, but I can think of just three that are good: Gettysburg, Glory!, and Shenandoah (the latter isn't on the same level as the first two, however).
Cold Mountain is a pile of bat poo. I can understand that somebody might have taste inclined to enjoy it as a cinematic production - if one's taste is inclined to movies of the sort - but its Civil War component is unarguably atrocious; without redeeming value.
I liked "Glory," but at times the dialogue got a bit too cloying -- audiences can get the racial harmony message without it being spoonfed to us! A very good movie, despite that. "Shenandoah" is another very good one, though of course it's not so much about the actual combatants. I did like "Ride with the Devil," which Anthropoid mentioned, except I was miffed at the title being so deceptive: with a title like that you don't expect more than half the movie to be cutesy scenes about one male character or another being romantically involved with Jewel. The movie was only 10% devil, by my estimate. Hell of a well done film, but it doesn't come as advertised.