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 (which is sometimes referred to as the Battle of Sharpsburg) produced the bloodiest single day of the Civil War. Lee suffered 11,000 casualties; McClellan, 13,000. Lee was forced to retreat, allowing the North to declare the battle a Union victory.