At Gettysburg, Union General Daniel Sickles disregards orders and loses much of his III Corps and his right leg

Anticipating a Confederate attack on the second day of the battle, Union General Meade had marshalled his forces along the high ground of Cemetery Ridge outside Gettysburg. Flamboyant General Daniel Sickles though he knew better and moved his entire III Corps forward to new positions a mile to the front.  Here he was met with much of the force of the Confederate attack and during heavy fighting that evening in the Peach Orchard, the Wheatfield, and Devil's Den much of his corps became casualties.  Sickles himself lost his right leg. (By John Osborne)