A deep ditch, into which the water of the river flowed, having over it a drawbridge connected with a barred gate, had been cut across the isthmus, so as to make the Hook, in reality, an island.  This ditch could be passed only at low water.  Thirty paces within it was a row of abattis running into the river; and some distance in front of it, is a creek fordable only in two places.

This difficulty of access, added to the remoteness of the nearest corps of the American army, impressed the garrison with the opinion that they were perfectly secure; and this opinion produced an unmilitary remissness in the commanding officer, which did not escape the vigilance of Lee.

On receiving his communications, General Washington was inclined to favour the enterprise they suggested; but withheld his full assent, until he was satisfied that the assailants would be able to make good their retreat.

The Hackensack, which communicates with the waters of the Hudson below New York, runs almost parallel with that river quite to its source, and is separated from it only a few miles.  This neck is still farther narrowed by a deep creek which divides it, and empties into the Hackensack below fort Lee.  West of that river runs the Passaick, which unites with it near Newark, and forms another long and narrow neck of land.  From Powles Hook to the new bridge, the first place where the Hackensack could be crossed without boats, the distance is fourteen miles; and from the North River to the road leading from the one place to the other, there are three points of interception, the nearest of which is less than two miles, and the farthest not more than three.  The British were encamped in full force along the North River, opposite to these points of interception.  To diminish the danger of the retreat, it was intended to occupy the roads leading through the mountains of the Hudson to the Hackensack with a select body of troops.

Every preparatory arrangement being made, the night of the eighteenth of August was fixed on for the enterprise.  A detachment from the division of Lord Stirling, including three hundred men designed for the expedition, was ordered down as a foraging party.  As there was nothing unusual in this movement, it excited no suspicion.  Lord Stirling followed with five hundred men, and encamped at the new bridge.

[Sidenote:  The British post at Powles Hook surprised by Major Lee and the garrison made prisoners.]

Major Lee, at the head of three hundred men, took the road through the mountains which ran parallel to the North River; and, having secured all the passes into York Island, reached the creek which surrounds the Hook between two and three in the morning.  He passed first the creek, and then the ditch undiscovered; and, about three in the morning, entered the main work, and with the loss of only two killed and three wounded, made one hundred and fifty-nine prisoners, including three officers.  Very few of the British were killed.  Major Sutherland, who commanded the garrison, threw himself with forty or fifty Hessians into a strong redoubt, which it was thought unadviseable to attack, because the time occupied in carrying it might endanger the retreat.  Wasting no time in destroying what could easily be replaced, Major Lee hastened to bring off his prisoners and his detachment.