I will say, of all the battlefields (and I do mean all) I've toured, Antietam is the hardest to get through, mostly because the land is so vastly different from the way it was back in the 19th century. There are whole forests that are no longer there (cleverly labeled, like they're saying, "Pretend there's a bunch of trees here. Now pretend that you are standing on a rise in the topography that isn't there anymore. Now pretend that when you face east there isn't a honkin' big war memorial blocking your view...")
"There he stands, like a Corn Dog."
But I can't 'splain it any better than Darkgarden: