When General Howe retreated from the White Plains, he halted his whole army on the North River, between Dobbs' Ferry and Kingsbridge, where he remained for some time. Having effected so little of the great business that brought him here, and the season allowing him time for it, most men were of opinion, that the next attempt would be, to get possession of Philadelphia by a forced march through the Jerseys, whilst a fleet should be sent up the Delaware to facilitate the enterprise. To guard against such a manoeuvre, General Washington crossed the North River with all the battalions, that had been raised to the westward of it, leaving General Lee, with the eastern troops, to guard the pass of the Highlands on Hudson River. In this situation of things, General Howe made a sudden attack upon Fort Washington, with the greatest part of his army, and carried it with considerable loss, making nearly three thousand of our men prisoners. By this event, it became unnecessary longer to hold Fort Lee, or Fort Constitution, as it was formerly called, which is on the west side of the North River, nearly opposite Fort Washington. It had therefore been determined to abandon Fort Lee, but before the stores could be all removed, the enemy came suddenly upon it, and the garrison retreated, leaving some of their baggage and stores behind. About this time General Howe became possessed of a letter, (by the agency of some wicked person, who contrived to get it from the express) written by General Washington to the Board of War, in which he had given an exact account when the time of service of all our battalions would expire, and his apprehensions, that the men would not re-enlist without first going home to see their families and friends. Possessed of this intelligence, the opportunity was carefully watched, and a vigorous impression actually made at the very crisis, when our army in the Jerseys was reduced to 3000 men by the retiring of numbers, and the sickness of others; and before militia could, in this extensive country, be brought up to supply their places, the enemy marched rapidly on through the Jerseys, whilst our feeble army was obliged to retreat from post to post until it crossed the Delaware at Trenton, where about 2500 militia from the city of Philadelphia joined the General.