Roger Fenton was one of the earliest war photographers. He documented the Crimean war. His photographs include more war landscapes than the actions of war, mainly because cameras were very slow back then. The action would have been over by the time he could click a picture. You can see the landscape of that time and the way that war took place.
Matthew Brady did not himself click many of the pictures of war. There was a group of twenty photographers who clicked pictures and no one will know which pictures were clicked by him in real life. I think this is not a good practice because everyone does not see your real work and imagination as a photographer. But the photographs clicked by this team are of the violent side of the war like devastated places and dead people.
Alexander Gardner was Brady’s assistant for many years. He also clicked pictures of violence, dead people and the negative aspects of war.
Robert Capa is one of the most famous war photographers. His photographs are completely different than those of Fenton, Brady and Gardner. Some of his pictures document the wars in action while on the battlefield, but mostly his work revolved around the everyday life during the war. He used photography as a medium to document the lives of common people. His pictures are like a photo-story of the impact war had on ordinary people’s lives.