The Battle of Shiloh was one of the bloodiest battles of the Civil War; it was fought on April 6-7, 1862 near a small church along the Tennessee River. The casualties were so high at Shiloh that they exceeded all previous wars the U.S. had been in to this point: the Revolutionary War, the War of 1812, and the Mexican American War COMBINED! There were around 24,000 casualties in this two day battle.