September 17, 1862 remains the bloodiest day in American history. On that day near Sharpsburg, Maryland, the Confederate Army of Northern Virginia and the Union Army of the Potomac suffered combined casualties of nearly 26,000, including nearly 5500 dead. Although tactically a draw, the fact that Robert E. Lee had been turned back after a string of victories beginning in the spring permitted Lincoln to issue the preliminary Emancipation Proclamation, which changed the character of the war. I wrote a piece on Antietam as part of my series on the Civil War for the Ashbrook Cetner in Ashland, Ohio. It is here.