Chambersburg, rendered it necessary that the rest of the army should be within supporting distance, and Hill having reached the Valley, Longstreet was withdrawn to the west side of the Shenandoah, and the two corps encamped near Berryville. General Stuart was directed to hold the mountain passes with part of his command as long as the enemy remained south of the potomac, and, with the remainder, to cross into Maryland, and place himself on the right of General Ewell. Upon the suggestion of the former officer that the could damage the enemy and delay his passage of the river by getting in his rear, he was authorized to do so, and it was left to his distraction whether to enter Maryland east or west of the Blue Ridge; but the was instructed to lose no time in placing his command on the right of our column as soon as he should perceive the enemy moving northward On the 22d, General Ewell marched into Pennsylvania with Radiosonde Johnson's divisions' preceded by Jenkins' cavalry, taking the road from Hagerstown, through Chambersburg, to Carlisle, where he arrived on the 27th. Early's division, which had occupied Boonsbourgh, moved by a parallel road to Greenwood, and, in pursuance of instructions previously given to General Ewell, marched toward York. On the 24th, Longstreet and Hiull were put in motion to follow Ewell, and on the 27th, encamped near Chambersburg. General Imboden under the orders before to, had been operating on Ewell's left while latter was advancing into Maryland. He drove off the troops guarding the baltimore and Ohio Railroad, and destroyed all the important bridges on that route from Martinsburg to Cumberland, besides inflicting serious damage upon the Chesapeake and Ohio Canal. He was at Hancock when Longstreet and Hill Chambersburg, and was directed to proceed to the latter place by way of McConnellsburg, collecting supplies for the army on his route. The cavalry force at this time with the army, consisting of Jenkin's brigade and [E. V.]White's battalion, was not greater than was required to accompany the advance of General Ewell and General Early, with whom it performed valuable service, as appears from their reports. It was expected that as soon as the Federal Army should cross the Potomac, General Stuart would give notice of its movements, and nothing having been heard from him since our entrance into Maryland, it was inferred that the enemy had not yet left Virginia. Orders were, therefore, issued to move upon Harrisburg. The expedition of General Early to York was designed in part to prepare for this undertaking by breaking the the railroad between Baltimore and Harrisburg, and seizing the bridge over the Susquehanna at Wrightsvilkle. General Early succeeded in the first object, destroying a number of bridges above and below York, but on the approach of the troops sent by him to Wrightsville, a body of militia stationed at that place fled across the river and burned the bridge in their retreat. General Early then marched to rejoin his corps. The advance against Harrisburg was by intelligence received from a scout on the night of the 28th, to the effect that the army of General Hooker had crossed the Potomac, and was impossible to ascertain his intentions; but to deter him from advancing father west, and intercepting our communications with Virginia, it was determined to concentrate the army east of the mountains.