I find it interesting that the budding media of the time came into play in a huge way by bringing the horrors of war to audiences far removed from it. Wartime photographers Matthew Brady, Timothy O’Sullivan and Alexander Gardner were, in a way early cameramen, not too unlike the media of today. Photographs are, indeed, "worth a thousand words."
I guess newspapers were widely read at that time and that is how the photographs were published? How do you think the photos effected public opinion about WWI? My friend tells me his family watched the Vietnam war footage at dinner time every day on tv news. That would be horrible. I am sure those news casts had a lot to do with the public opinion turning against that war.
The media is an extremely powerful tool, especially in times of war. If used to the advantage of the government, it could completely distort the facts of the war and keep the funding pouring in and the president with little worry of reelection. On the other hand, if completely true about the war, the media can cause extreme dissent among the people regarding the war. The power of information, gentlemen.
Most of those pictures the photographers you mentioned were able to take are chilling. It *does* tend to be a bit upsetting that some of them felt the need to disturb and reposition the dead to get the most bang for their buck though, doesn't it? (i.e. the sharpshooter photo from Devil's Den and many others.)
You could say that a big portion of the war is fought outside of the battlefield for the reasons you stated. Nowadays you have to be very skilled in reading the media and try to form your own opinion on things. There's just so much information forced to you.