Retreat From Gettysburg - Background

Background

The culmination of the three-day Battle of Gettysburg was the massive infantry assault known as Pickett's Charge, in which the Confederate attack against the center of the Union line on Cemetery Ridge was repulsed with significant losses. The Confederates returned to their positions on Seminary Ridge and prepared to receive a counterattack. When the Union attack had not occurred by the evening of July 4, Lee realized that he could accomplish nothing more in his Gettysburg Campaign and that he had to return his battered army to Virginia. His ability to supply his army by living off the Pennsylvania countryside was now significantly reduced and the Union could easily bring up additional reinforcements as time passed, whereas he could not. Brig. Gen. William N. Pendleton, Lee's artillery chief, reported to him that all of his long-range artillery ammunition had been expended and there were no early prospects for resupply. However, despite casualties of over 20,000 officers and men, including a number of senior officers, the morale of Lee's army remained high and their respect for the commanding general was not diminished by their reverses.

Lee began his preparations for retreat on the night of July 3, following a council of war with some of his subordinate commanders. He consolidated his lines by pulling Lt. Gen. Richard S. Ewell's Second Corps from the Culp's Hill area back through the town of Gettysburg and onto Oak Ridge and Seminary Ridge. His men constructed breastworks and rifle pits that extended 2.5 miles from the Mummasburg Road to the Emmitsburg Road. He decided to send his long train of wagons carrying equipment and supplies, which had been captured in great quantities throughout the campaign, to the rear as quickly as possible, in advance of the infantry. The wagon train included ambulances with his 8,000 wounded men who were fit to travel, as well as some of the key general officers who were severely wounded, but too important to be abandoned. The great bulk of the Confederate wounded—over 6,800 men—remained behind to be treated in Union field hospitals and by a few of Lee's surgeons selected to stay with them.

There were two routes the army could take over South Mountain to the Cumberland Valley (the name given to the Shenandoah Valley in Maryland and Pennsylvania), from where it would march south to cross the Potomac at Williamsport, Maryland: the Chambersburg Pike, which passed through Cashtown in the direction of Chambersburg, and; the shorter route through Fairfield and over Monterey Pass to Hagerstown. Fortunately for the Confederate army, it now had its full complement of cavalry available for reconnaissance and screening activities, a capability it lacked earlier in the campaign while its commander, Maj. Gen. J.E.B. Stuart, was separated from the army with his three best cavalry brigades on "Stuart's ride".

Unfortunately for the Confederate Army, however, once they reached the Potomac they would find it difficult to cross. Torrential rains that started on July 4 flooded the river at Williamsport, making fording impossible. Four miles downstream at Falling Waters, Union cavalry dispatched from Harpers Ferry by Maj. Gen. William H. French destroyed Lee's lightly guarded pontoon bridge on July 4. The only way to cross the river was a small ferry at Williamsport. The Confederates could potentially be trapped, forced to defend themselves against Meade with their backs to the river.