The terrain around the college town of Gettysburg, Pennsylvania offered excellent defensive positions for an army who might want to fight there. To the south of town, Cemetery Hill, Cemetery Ridge and Culp's Hill all offered strong protection. Three areas to the west of the town--Seminary Ridge, McPherson Ridge and Herr Ridge--all served as adequate positions for the delaying action initiated by Union cavalry General John Buford on the first day. Buford saw that if the Union army was forced to abandon the western ridges, the protection offered to the south would be an excellent spot to make a stand. General Winfield Scott Hancock, who assumed command of the Union army until new commander George Meade arrived, stated that
"I think this the strongest position by nature upon which to fight a battle that I ever saw... I select this as the battle-field."
General Robert E. Lee also recognized the significance of Cemetery Hill. He ordered new corps commander Dick Ewell to take the hill at the end of the first day--"if practicable." Ewell did not understand Lee's order--Lee actually meant for Ewell to take the hill immediately--and he decided against making the attack. Most historians agree that if General Stonewall Jackson had still been alive and in command (Ewell had replaced Jackson, who died from wounds received at the Battle of Chancellorsville), Jackson would have taken the lightly defended Cemetery Hill, and the ensuing battle would have gone much differently for the Confederates. Ewell's lack of action is considered one of the great "lost opportunities" in all warfare.
Two other geographical areas, the Devil's Den and Little Round Top, also became crucial Union positions. Lee ordered both of them taken, but his losses in the Devil's Den were heavy. Little Round Top, at the far south of the battlefield, was initially undefended; Lee saw its importance, recognizing that Confederate artillery would have a clear shot at the Union's flank, which could also be turned and routed by rebel infantry. But before Confederate troops could arrive, a brigade under Colonel Strong Vincent marched to the hill without orders. Vincent's initiative would prove crucial to the eventual outcome of the battle.
Lee's greatest mistake was making the monumental Pickett's Charge on the third day. The ground chosen for the assault was a mile-long stretch of open field which the Confederates would have to cross. They emerged from Spangler's Woods on Seminary Ridge, aiming for a "clump of trees" on Cemetery Ridge. The Union artillery and infantry were waiting, however, and as the 15,000 Confederates approached, their ranks were decimated. Union troops and artillery were able to flank the attackers as they advanced, causing more destruction to the men led by General George Pickett. Only a handful of Confederates reached their objective, and the attack suffered casualties of more than 50%.
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