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 American Civil War doesn't even pass the test of the bloodiest civil war in the Americas. This dubious honor is held by the Mexican Revolution of 1910, with between 1 and 2 million casualties.