Fields of Death Fought with mass armies and new weapons, the Civil War took a huge toll in human lives, as evidenced by this grisly photograph of a small section of the battlefield at Antietam, Maryland. The most costly single-day battle in American history, it left 22,700 dead, wounded, and missing Confederate and Union soldiers. After the equally bloody three-day battle at Shiloh, Tennessee, in April 1862, General Ulysses Grant surveyed a field “so covered with dead that it would have been possible to walk … in any direction, stepping on dead bodies, without a foot touching the ground.” Library of Congress.