A Harvest of Death, Gettysburg, Pennsylvania.
Dead soldiers litter the ground in the aftermath of the Battle of Gettysburg, which took place from July 1 to 3, 1863. Timothy O'Sullivan took this photograph, titled "A Harvest of Death, Gettysburg, Pennsylvania," and it became one of the most iconic images of the Civil War. This albumen print was made by Alexander Gardner from O'Sullivan's glass-plate negative and used in Gardner's Photographic Sketch Book of the War (1866), a two-volume work that included 100 mounted photographs of the conflict.
Gardner, a Scottish-born photographer, worked for the renowned Mathew Brady photographic studio in Washington, D.C., from 1856 to 1862, until he opened a rival studio. Gardner poached a number of Brady's best photographers for his own studio, including Timothy O'Sullivan, and after the war produced his illustrated Sketch Book.