General Putnam was ordered to reenforce General McDougall, who was in command at the hill; but before he arrived the British had flanked the Americans and driven them from their position. Putnam's men covered their retreat by firing at the British and Hessians from behind fences and trees, Indian and Ranger fashion, and that night Washington practically began his famous retrograde movement to Fort Washington and Manhattan Island. "By folding one brigade behind another," in rear of those ridges he had fortified, he "brought off all his artillery, stores, and sick, in the face of a superior foe." He took position, first, at North Castle Heights, which he deemed impregnable; but after a few days the British left for the Hudson, with the purpose (as was afterward ascertained, and at the time divined by Washington) of attacking forts Washington and Lee and invading New Jersey. In anticipation of this move Putnam was detached with about four thousand men and ordered into New Jersey. Crossing the Hudson, he penetrated inland as far as Hackensack, near which place he encamped and awaited developments. General Lee was left at North Castle Heights with seven thousand men to watch the movements of the foe, while Washington followed after Putnam to Hackensack. He was shortly recalled to the Hudson by a despatch informing him that the British were before Fort Washington in overwhelming force, and had demanded a surrender. Brave Colonel Magaw, in command of the garrison, refused a reply until he had consulted his superior officers, and as General Greene, in charge of both forts, was of the opinion that they could be held, the result was the storming of the fort and the loss of more than two thousand men. The assault of the British, who had threatened to put the garrison to the sword, was witnessed by Washington, Greene, and Putnam from the west bank of the Hudson. Their distress may be imagined at beholding the slaughter that ensued, and there must have been some searching self-questioning by the Commander-in-Chief as to the wisdom of his policy, by which his divided forces became such an easy prey to the foe. Lee could hardly be induced to leave his secure retreat, from which he departed only after repeated requests from Washington, whose great reliance at this time was sturdy Israel Putnam. He assisted at the evacuation of Fort Lee (now rendered useless by the loss of its sister fort across the river), and piloted the commander and his friends to his camp at Hackensack. British troops under Lord Cornwallis had landed above Fort Lee at the base of the Palisades, and were now coming down to attempt to cut off the Americans before they could extricate themselves from the marshes lying between the Hudson and the Hackensack rivers. The latter left so precipitately that their fires were burning, with camp kettles over them, and tents still standing, when the British reached Fort Lee.