As Union troopers from the 5th Michigan Cavalry approached Emack's men, the cannon opened fire and eight of the Marylanders conducted a mounted charge into the head of the Union column. Emack from the 1st Maryland Cavalry Battalion, along with a single cannon. The remaining Confederate force on the road up the hill to the Pass consisted of a detachment of 20 dismounted cavalrymen under Capt. A single 12-pounder Napoleon of Courtney's Battery fired a shot at the Union horsemen, but the gunners withdrew before they could be attacked. Despite being warned of a Confederate artillery placement ahead, Kilpatrick ordered his entire force to advance. Custer, a brigade commander under Kilpatrick, received intelligence from a local civilian that the rear of Ewell's wagon train was approaching a large summer resort hotel named Monterey Springs, which sat atop the Pass. The 7th Virginia was soon recalled, replaced by the 4th North Carolina Cavalry of Robertson's Brigade. Stuart allowed the 6th and 7th Virginia Cavalry regiments and a battery of horse artillery under Capt. Recognizing the vulnerability of Ewell's immense wagon train in the narrow Monterey Pass, Jones asked permission from Stuart to use his entire brigade to defend it. Stuart understood the importance of securing the mountain passes and he assigned the primary responsibility to the cavalry brigades of Brig. George Pickett's division, which was moving to the rear as escorts for the Union prisoners of war from the battle. The wagons headed for Monterey Pass followed the route of Maj.
The first used the Cashtown Gap, the second the Fairfield Gap, and the third the Monterey Pass.
He divided his wagons into three columns. However, the first traffic on the Fairfield Road had begun on the evening of July 3, when Ewell, concerned about the logistical challenges of the impending retreat, sent his corps trains and herds of captured cattle ahead of his main body. Departing in the dark, Lee had the advantage of getting several hours head start and the route from the west side of the battlefield to Williamsport was about half as long as the ones available to the Army of the Potomac. Lee accompanied Hill at the head of the column. Hill's Third Corps headed out onto the Fairfield Road, followed by Lt. While Imboden's wagons moved northwest, Lee designated a shorter route for his three corps: southwest through Fairfield and over Monterey Pass to Hagerstown. Imboden over the Chambersburg Pike, which passed through Cashtown in the direction of Chambersburg and Hagerstown, Maryland. He sent the majority of the wagons and ambulances under the direction of Brig.
Prior to the movement of the infantry and artillery, however, Lee was concerned with removing his long train of wagons, supplies, and wounded men over South Mountain and into the Cumberland Valley. 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. Meade's Army of the Potomac did not counterattack 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. Lee ordered his Confederate Army of Northern Virginia to begin withdrawing from Gettysburg following his army's defeat on July 3, 1863. For additional combat in the area of this military engagement, see Monterey Pass.