Timothy O’Sullivan (c. 1840–1882) was born in Ireland and immigrated to New York City with his parents. As a photographer, he was widely known for his work related to the Civil War.

A Harvest of Death

While Antietam saw the single bloodiest day of the Civil War, the Battle of Gettysburg, a major turning point in the Civil War, was the bloodiest battle overall, with a total of fifty-one thousand casualties. The battle was fought over three days, July 1–3, 1863. Printed in Alexander Gardner’s 1866 collection, Gardner’s Photographic Sketchbook of the War, this photograph was taken by Sullivan on the battlefield.