1863: Union troops repelled a massive artillery assault on Cemetery Ridge during the third day of the Battle of Gettysburg in southern Pennsylvania. During the early morning hours Confederate General Robert E. Lee ordered General Longstreet to prepare General Pickett's troops for the assault. After two hours of heavy shelling, Confederate Colonel Alexander sent word to General Pickett that the Union troops were withdrawing and encouraged him to come quickly in the interval. Pickett sent his note to General Longstreet who, based on Lee's orders and despite his own reservations, approved the charge. The attack, commonly known as Pickett's Charge or Longstreet's Assault, was an attempt to penetrate the center of Union forces on Cemetery Ridge. During the attack, only one Confederate brigade temporarily reached the top of the ridge - afterwards called the high watermark of the Confederacy - led by Brigadier General Lewis Armistead who, just before being shot, yelled, "Give them cold steel, boys!" The charge ultimately proved disastrous for the Confederates, with casualties approaching 60 percent. As a consequence, Confederate General Robert E. Lee was forced to retreat and ultimately abandon his attempt to reach Washington, D.C. via Pennsylvania. (Source: Library of Congress)