The bloodiest day in American history takes place as the armies of Robert E. Lee and George B. McClellan fight to a standoff near Sharpsburg, Maryland, along Antietam Creek.

The Shenandoah Valley: Sigel Ousted
May 19, 1864 – Major General John C. Breckinridge’s Confederates began leaving the Shenandoah Valley, and Major General Franz Sigel was replaced as Federal commander