mandelbug definition: Noun (plural mandelbugs) 1. (computing) A software bug whose behaviour appears to be chaotic. ...
The bloodiest single day of battle was Antietam (26,134 casualties). The bloodiest battle, however - which lasted three days - was Gettysburg (51,112 casualties). July 21, 1861.
The Battle of Antietam is considered the bloodiest day in the history of American war, with over 23,000 soldiers wounded, killed, or missing. The Union held off the invasion of the Confederacy, although President Abraham Lincoln was very unhappy that the Confederates were allowed to retreat back to Virginia.