Matthew Brady

[The Straight Story]

At the peak of his success as a portrait photographer, Brady turned his attention to the Civil War. Planning to document the war on a grand scale, he organized a corps of photographers to follow the troops in the field. Friends tried to discourage him, citing battlefield dangers and financial risks, but Brady persisted. He later said, "I had to go. A spirit in my feet said 'Go,' and I went."

...

In 1862, Brady shocked America by displaying his photographs of battlefield corpses from Antietam, posting a sign on the door of his New York gallery that read, "The Dead of Antietam." This exhibition marked the first time most people witnessed the carnage of war. The New York Times said that Brady had brought "home to us the terrible reality and earnestness of war."

http://lcweb2.loc.gov/ammem/cwphtml/cwbrady.html