At daylight on July 4th, after the dust had settled at Gettysburg, the horrible task facing the soldiers that remained were burying the dead and collecting arms scattered over the battlefield. The rain set in and high winds swept across the battlefield making the bivouac of soldiers miserable. With the morning of July 5th dawning, the soldiers of the Third Corps would continue caring for the wounded. While his soldiers at Gettysburg carried out the monotonous tasks that had to be done after battle, the wounded Third Corps commander General Daniel Sickles, made his way to Washington where he rested and was visited by the President.
By July 5th, General George Meade issued orders to his corps commanders for a withdraw from Gettysburg. All reports that came to General Meade stated that the Confederate army had already retreated from Gettysburg and was on the road heading in the direction of South Mountain. General David B. Birney assumed temporary command of the Third Corps, and seeing to it that General Meade’s orders were carried out, his new command pursued the Confederate army.
The following morning, the Third Corps was put into motion but halted a short way from Gettysburg, on their way to Emmitsburg. Some reports state that the Third Corps returned to their original position. The roads that carried the Third Corps to Gettysburg were blocked by the Eleventh Corps, the First Corps and the Fifth Corps. The Sixth Corps were also ordered to march from Fairfield to Emmitsburg. Emmitsburg would see two-thirds of the Army of the Potomac marching through during the night of July 6th and into the morning of July 7th.
By three o’clock in the morning on July 7th, the Third Corps began its march to Emmitsburg. Arriving at Emmitsburg, several of the brigades took pleasure in resting in the fields surrounding the town. Unfortunately for the men, the rest was a miserable one, as they had no protection from the elements of the weather, nor found any comfort in resting on the muddy ground. Shortly after 1:00 p.m. the Third Corps began its march on the Emmitsburg Road to Mechanicstown, known as Thurmont today, bivouacking there for the night at around sunset.
At six o’clock in the morning on July 8th, the Third Corps resumed their line of march toward Frederick. As the Third Corps neared Lewistown, the soldiers began marching toward Hamburg Pass, where they found the road badly tore up. The route was promptly changed, and they marched to Frederick City. The 141st Pennsylvania brought up the rear of the Corps and noted that the country side was a vast “sea of mud.” The march was a hard one, as the soldiers carried their guns with the muzzles pointed toward the ground, their blanket rolls were soaking wet and because of that, made heavier, and those who chose to carry their knapsacks found it be bulky. The march halted at 10:00 p.m. that night with the Third Corps resting on the road to Middletown, just outside of Frederick.
At 4:00 a.m. on July 9th, the Third Corps began marching toward Middletown, bringing up the rear of the Army of the Potomac. Upon reaching Middletown, the Third Corps were issued rations and continued to march to South Mountain, where they were to march over to Fox’s Gap at approximately 10:00 a.m. The men rested upon the mountainside until about 6:00 p.m. when they were ordered to resume their march. At 7:00 p.m. orders were given for the Third Corps to encamp west of Fox’s Gap, while the rear of the Corps encamped on the South Mountain Battlefield at Fox’s Gap.
The next morning, at six o’clock, the march toward the Antietam Creek began. The soldiers passed through Keedysville, and halted near General Meade’s headquarters near the Devil’s Backbone. The march was again harsh and the soldiers were thankful when they were ordered to bivouac at 9:30 that night. Unfortunately for the men, again, orders were issued, and the march was resumed. Finally, at 2:00 a.m. orders were again given to bivouac for the night, this time near Poolesville.
At 6:00 a.m. on July 11th, the Third Corps began to go into position in support of the Fifth Corps. At four o’clock that evening more alignments were made and the soldiers of the Third Corps bivouacked for the night. The following morning, the Third Corps remained in the same position until about noon when portions of the Third Corps marched about one mile, went into bivouac, and massed in a woods about 1½ miles to the rear of Marsh Creek. During the day, on July 13th, not much was recorded, and it is presumed that the Third Corps was still encamped in the same area.
At dawn on July 14th, the Third Corps was ordered to support the Twelfth Corps, marching about one mile before encamping for the night. The Confederate army had already crossed the Potomac River during the night of July 13th. General Meade issued orders for a withdraw from Williamsport, and to cross the Potomac River at, or near, Sandy Point.
On July 15th, the Third Corps marched from Williamsport to Sharpsburg. After passing through Sharpsburg, the Third Corps crossed over what had become Burnside’s Bridge, marching about a half of a mile and were bivouacked at 1:00 p.m. The next day, the Third Corps began their march into Pleasant Valley at six o’clock in the morning and marched to Brownsville, near Maryland Heights, where they encamped at 2:00 p.m. Late in the day on July 17th, the Third Corps marched to Harper’s Ferry, crossing the Potomac River on pontoons, and marched another five miles before encamping for the night.
At this point, the Pennsylvania Campaign ended for the Third Corps. They would continue their march to Hillsborough, Virginia, where the South Mountain range begins in a series of rolling hills known as Short Hill Mountain.