Owing to the strength of the enemy's position and the exhaustion of our ammunition, a renewal of the engagement could not be hazarded, and the difficulty of procuring supplies rendered it impossible to continue longer where we were. Such of the wounded as could be removed and a part of the arms collected on the field were ordered to Williamsport. The army remained at Gettysburg during the 4th, and at night began to retire by the road to Fairfield, carrying with it about four thousand prisoners. Nearly two thousand had been previously paroled; but the numerous wounded that had fallen into our hands after the first and second day's engagements were left behind. Little progress was made that night, owing to a severe storm, which greatly embarrassed our movements. The rear of the column did not leave its position near Gettysburg until after daylight on the 5th. The march was continued during that day without interruption by the enemy, except an unimportant demonstration upon our rear in the afternoon, when near Fairfield, which was easily checked. The army, after a tedious march, rendered more difficult by the rains, reached Hagerstown on the afternoon of the 6th and morning of the 7th of July.
The Potomac was so much swollen by the rains, that had fallen almost incessantly since our army entered Maryland, as to be unfordable. A pontoon-train had been sent from Richmond, but the rise in the river gave to it a width greater than was expected, so that additional boats had to be made by the army on its retreat. Our communication with the south side was thus interrupted, and it was found difficult to procure either ammunition or subsistence, the latter difficulty being enhanced by the high water impeding the working of the mills. The trains with the wounded and prisoners were compelled to wait at Williamsport for the subsiding of the river or the construction of additional pontoon-boats. The enemy had not yet made his appearance, but, as he was in a condition to obtain large reënforcements and our want of supplies was daily becoming more embarrassing, it was deemed advisable to recross the river. By the 13th a good bridge was thrown over at Falling Waters. On the 12th Meade's army approached. A position had been previously selected to cover the Potomac from Williamsport to Falling Waters, and an attack was awaited during that and the succeeding day. This did not take place, though the two armies were in close proximity, the enemy being occupied in fortifying his own lines.
General Meade, in his testimony before the Committee on the Conduct of the War, said that he ordered an attack on our forces on the morning of the 14th, and, if it had been made, it was his opinion that "it would have resulted disastrously." When asked the reasons for that opinion, he replied:
"If I had attacked the enemy in the position which he then occupied—he having the advantage of position, and being on the defensive, his artillery in position, and his infantry behind parapets and rifle-pits—the very same reasons and causes which produced my success at Gettysburg would have operated in his favor there, and be likely to produce success on his part."
Our preparations being completed, and the Potomac, though still deep, being pronounced fordable, the army commenced to withdraw to the south side on the night of the 13th. Ewell's corps forded the river at Williamsport, those of Longstreet and Hill crossed upon the bridge. Owing to the condition of the roads the troops did not reach the bridge until after daylight on the 14th, and the crossing was not completed until 1 P.M., when the bridge was removed. General Lee said that the enemy offered no serious interruption, and the movement was attended with no loss of material except a few disabled wagons and two pieces of artillery, which the horses were unable to move through the deep mud. During the slow and tedious march to the bridge, in the midst of a violent storm of rain, some of the men lay down by the way to rest. Officers sent back for them failed to find many in the obscurity of the night, and these, with some stragglers, a few of Heth's division most remote from the bridge, were captured. On the following day the army marched to Bunker Hill, in the vicinity of which it encamped for several days. Owing to the swollen condition of the Shenandoah River, the campaign which was contemplated when the Potomac was recrossed, could not be immediately commenced. Before the waters had subsided, the movements of the enemy required us to cross the Blue Ridge and take position south of the Rappahannock.
The strength of our army at Gettysburg is stated at 62,000 of all arms.[79] The report of the Army of the Potomac under General Meade, on June 30, 1863, states the force present at 112,988 men. Before the Committee on the Conduct of the War, General Meade, in reference to his force at Gettysburg, said, "Including all arms of the service, my strength was a little under 100,000 men—about 95,000."
If the strength of General Lee's forces, according to the last accessible report before the movement northward, be compared with that made after his return into Virginia, there is a decrease of nineteen thousand of the brave men who had set the seal of invincibility upon the Army of Northern Virginia.
General Lee, in his report, noticing the large loss of men and officers, says:
"I can not speak of these brave men as their merits and exploits deserve. Some of them are appropriately mentioned in the accompanying reports, and the memory of all will be gratefully and affectionately cherished by the people in whose defense they fell.
"The loss of Major-General Pender is severely felt by the army and the country. . . . Brigadier-Generals Armistead, Barksdale, Garnet, and Semmes, died as they had lived, discharging the highest duty of patriots with devotion that never faltered, and courage that shrank from no danger."