Three corps, commanded respectively by Generals Howard, Slocum, and Meade, had been sent up the river, but marched at a sufficient distance from the hostile southern bank to avoid all observation. Arriving at Kelly's Ford, they began to cross, though it was in the night, and the men were compelled to wade in water up to their armpits. The moon, which shone brightly, assisted them most of the night, but went down before the entire force had crossed, when crossing had to be suspended until morning. Pontoons were brought up and laid, and so the remainder of the infantry and the cavalry corps crossed pleasantly. The column advanced towards the Rapidan, and Generals Howard and Slocum's commands crossed this stream at Germania Mills, and General Meade's at Ely Ford, below, and then all marched on roads which converge to the Chancellorsville House, a large brick edifice, which was used as a mansion and tavern, situated in a small clearing of a few acres, and which, with its few appendages of outbuildings, constituted the village known by that name. Other forces, including General Pleasonton, with nearly a brigade of cavalry, who guarded the flanks of the advancing columns, had crossed the river, and taken their position near Chancellorsville. By this wily movement General Lee's position on the Rappahannock had been entirely flanked; and, flushed with incipient success, General Hooker followed his great captains, and in the evening of the thirtieth of April he established his headquarters in the historic brick mansion above described. So completely absorbed was our general with the brilliancy of his advance that, in the moment of exultation, he forgot the dangers of his situation, and issued the following congratulatory order: HEADQUARTERS ARMY OF THE POTOMAC, Camp near Falmouth, Virginia, April 30, 1863. It is with heartfelt satisfaction that the commanding general announces to the army that the operations of the last three days have determined that our enemy must either ingloriously fly or come out from behind his defences and give us battle on our own ground, where certain destruction awaits him. The operations of the Fifth, Eleventh, and Twelfth Corps have been a succession of splendid achievements. By command of MAJOR-GENERAL HOOKER. S. WILLIAMS, _Assistant Adjutant-General_. It would seem as if the general had overlooked the fact that his army had but eight days' supplies at hand; that a treacherous river flowed between him and his depots; that he was surrounded by a labyrinth of forests, traversed in every direction by narrow roads and paths, all well known to the enemy, but unknown even to most of his guides; and that many of his guns of heaviest calibre, and most needed in a deadly strife, were on the other side the river.