During the 1777 encampment, Washington’s heavily entrenched stronghold at Middlebrook defied Howe’s massed British army of 18,000 and prevented a British movement against Philadelphia by land from June 14 to 30. The delay forced Howe to move by sea, with great loss of time. The last defenses of the American Capitol were not overcome until late November 1777, too late to assist Burgoyne, who was then forced to surrender at Saratoga on Oct. 17, 1777. During the second encampment in 1778-79, Clinton judged Middlebrook too strong and Washington’s troops too numerous, at 8,000, to be rashly attempted, while his own force of 22,000 remained in the New York-Rhode Island area.