When the Civil War began, Mathew Brady obtained permission for himself and his staff (which at various times included Alexander Gardner, George Bernard, John Reekie, and Timothy O'Sullivan, among others) to travel with the troops. He published all photographs, both by himself and others, under the name Brady & Co. Like most photographers during the war, Brady rarely photographed actual battles. Cumbersome camera equipment and slow exposure times made it difficult to capture action. Instead, they focused on the aftermath of the battle, military portraits, and scenes of camp life. Brady's experience as a studio photographer may have suggested the posed drama of The Sick Soldier [Smithsonian American Art Museum]. His picture of a Northern soldier being aided by another played to the collective trauma of mid-nineteenth century American households, most of whom, like Samuel Wilkeson, had suffered the loss of a relative or friend.
Merry A. Foresta American Photographs: The First Century (Washington, D.C.: National Museum of American Art with the Smithsonian Institution Press, 1996)