Explanation: Beginning early on the morning of September 17, 1862, Confederate and Union troops in the Civil War clash near Maryland's Antietam Creek in the bloodiest single day in American military history.
Of the ten bloodiest battles of the American Civil War, the Battle of Gettysburg in early July, 1863, was by far the most devastating battle of the war, claiming over 51 thousand casualties, of which 7 thousand were battle deaths.
