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.
Battle of Antietam. aka Battle of Sharpsburg was the bloodiest day in US history. The union won and kept the confederacy from moving further north. McClellan kept 4 divisions back, refusing to send them in to massacre the defeated Confederate troops.