Photographer Alexander Gardner set out to do at the Antietam battlefield in 1862 what no other photographer before him had attempted. He wanted to to document a battlefield before the dead had been cleared away. These were taken before newspapers could print photos. But not long after, the photos were publicly exhibited and for a culture that had never seen the morbidity of war, it must have been shocking.
You have to put yourself in their perspective. Those viewing these images had only heard that a war was happening, and that people died. Nameless people. People they never knew or never would know. Then take that sheltered perspective and look at these images. Suddenly the names don't matter, only the realization that these were people with families and loved ones. The people at the time had never seen documentary photos like this before, let alone ones of war.
"The images did not simply reveal the crumpled dead and deflated survivors in incredible detail; many of the images did so in 3-D. Gardner employed a new photographic technique at the time—the sterograph. Two lenses captured two photographs simultaneously, which provided a three-dimensional image when seen through a viewer. In parlors across America, people stood with their viewers and processed the reality of battle in unprecedented detail."