Shortly after midnight the whole Federal army had crossed Bull Run. No time was lost in posting batteries to command the bridge; and the rear guard bivouacked till daylight at a point two miles before reaching Centreville. Jackson at the same time led his troops to the north of Centreville, endeavoring to turn the Federals’ right, that their connection with Washington might thus be cut off. General Pope, anticipating such a movement, had drawn back his troops to Germantown, where, on September 1st, he fought a sharp engagement with the rebels, fiercely repulsing them. General Kearney was repelled in this engagement. As the darkness gathered around the combatants, he rode forward to reconnoitre, and passing the Union pickets, approached so close to the enemy that a rifleman’s bullet pierced his body, and he fell to the earth, dead. Here, also, fell Colonel George W. Pratt, of New York, while leading his regiment of Ulster county boys in its first charge. A more accomplished mind, or braver spirit, never yet was given to a country. The Army of Virginia was ordered to withdraw to Alexandria on the 2nd of September, a movement which made it necessary for General Burnside to evacuate Fredericksburg. Falmouth Station, containing large quantities of commissary stores, was destroyed. Three bridges across the Rappahannock met a similar fate; and Acquia Creek was shortly afterward abandoned, when the forces removed to Alexandria. At Alexandria, also, were concentrated the shattered divisions of the splendid Army of the Potomac, awaiting the arrival of Pope’s Army of Virginia. MOVEMENTS OF M’CLELLAN.