On June 30, 1863, the Headquarters of the Army of the Potomac moved from Middleburg to Taneytown as its corps and cavalry shifted across Maryland and Pennsylvania: the First Corps marched from Emmitsburg to Marsh Run; the Third Corps from Taneytown to Bridgeport; the Fifth Corps from Liberty by way of Johnsonville, Union Bridge, and Union to Union Mills; the Sixth Corps from New Windsor to Manchester; the Twelfth Corps from Taneytown and Bruceville to Littlestown; the First and Second brigades of the First Cavalry Division from near Fairfield by way of Emmitsburg to Gettysburg; the Second Cavalry Division from New Windsor to Westminster and then to Manchester; the Third Cavalry Division from Littlestown to Hanover; and the Artillery Reserve from Bruceville to Taneytown. Fighting took place at Hanover, Pennsylvania, with skirmishes at Westminster, Maryland, and at Fairfield and Sporting Hill near Harrisburg, Pennsylvania.