It was at Antietam, the blood-churning battle in Sharpsburg, Md., where more Americans died in a single day than ever had before, that one Union soldier recalled how “the piles of dead ... were frightful.” The Scottish-born photographer Alexander Gardner arrived there two days after the September 17, 1862, slaughter. He set up his stereo wet-plate camera and started taking dozens of images of the body-strewn country­side, documenting fallen soldiers, burial crews and trench graves. Gardner worked for Mathew Brady, and when he returned to New York City his employer arranged an exhibition of the work. Visitors were greeted with a plain sign reading “The Dead of Antietam.” But what they saw was anything but simple. Genteel society came upon what are believed to be the first recorded images of war casualties. Gardner’s photographs are so sharp that people could make out ­faces. The death was unfiltered, and a war that had seemed remote suddenly became harrowingly immediate. Gardner helped make Americans realize the significance of the fratricide that by 1865 would take more than 600,000 lives. For in the hallowed fields fell not faceless strangers but sons, brothers, fathers, cousins and friends. And Gardner’s images of Antietam created a lasting legacy by establishing a painfully potent visual precedent for the way all wars have since been covered.

See Alexander Gardner's images of the Civil War's gruesome reality

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  Alexander Gardner—Library of Congress

  Elk Mountain, Md. Signal tower overlooking Antietam battlefield.

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  Alexander Gardner—Library of Congress

  Antietam, Md. Allan Pinkerton, President Lincoln and Major General John A. McClernand.

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  Alexander Gardner—Library of Congress

  Antietam, Md. Allan Pinkerton ("E.J. Allen") of the Secret Service on horseback.

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  Alexander Gardner—Library of Congress

  Keedysville, Md., vicinity. Smith's barn, used as a hospital after the battle of Antietam.

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  Alexander Gardner—Library of Congress

  Antietam, Md. Another view of Antietam bridge.

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  Alexander Gardner—Library of Congress

  Harper's Ferry, W.Va. View of town; railroad bridge in ruins.

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  Alexander Gardner—Library of Congress

  Antietam, Md. Confederate dead in a ditch on the right wing used as a rifle pit.

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  Alexander Gardner—Library of Congress

  Antietam, Md. Bodies of Confederate dead gathered for burial.

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  Alexander Gardner—Library of Congress

  Probably taken on the afternoon of Sept. 18 (the day after the battle). A man with binoculars on the hill in front of McClellan's headquarters looks toward Antietam Creek. The smoke is from campfires, and the inactive artillery unit is thought to be General Andrew A. Humphreys' Fifth Corps division.

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