Photographer of War
Evidence 1: Hey took pictures during the war very close while the war was going on.
His first popular photo's of the conflict were at the first battle of bull run in which he got so close to the action that he barely avoided capture
Evidence 3: In 1856 Brady placed an ad in the New York Herald paper offering the produce"Photographs, ambrotypes and dayuerreotypes"
On September 19, 1862, two days after the battle of Antiertan, one of the bloodiest wars ever. He sent a photographer and his assistant to take pictures of the carnage.