The ending of the Suffolk campaign allowed Lee to concentrate his army once again. With the addition of Longstreet's two divisions, he could resume offensive movements given up in the wake of the Maryland campaign. This time Pennsylvania was the goal. Lee hoped to take the scene of operations away from the Rappahannock River, where it had been planted for six months. Gathering food was another consideration, and generally causing havoc on free soil was yet another. The Pennsylvania campaign shook up the North. It was the Confederacy's biggest incursion into free territory during the war.
Lee planned to enter Northern soil by way of the lower Shenandoah Valley, but a modest Union garrison at Winchester barred the way. An old city in the middle of the expansive lower end of the Valley, Winchester was the scene of two battles fought during the preceding year as part of Stonewall Jackson's Valley campaign. Its strategic location meant that the town would change hands more than a dozen times during the war and three more battles would be fought in and near its rows of substantial houses.
Winchester was not an easy post to fortify. The landscape is generally level with a few prominent hills and ridges, but they are no more than about 200 feet high and are not arrayed in a manner to allow a defending force to construct a systematic line of works. It was not possible to build a cohesive system of defenses with no holes in its perimeter.1
Federal troops had first entered Winchester on March 11, 1862, but Jackson drove them out in late June near the end of his Valley campaign. After Jackson evacuated the Valley to join Lee for the Seven Days, Col. Abram S. Piatt's Federal brigade reoccupied the town and began to fortify. Fort Garibaldi (later renamed Fort Milroy) was the major work constructed just west of Winchester on a prominent hill. Wood from the nearby home of James S. Mason, of the Mason-Slidell affair of 1861, was used in its construction. Trees between the fort and the town were cut down for a clear field of fire. Julius White replaced Piatt as Federal commander at Winchester on July 28, but he