Some changes made in the stations of the British ships and troops having relieved Washington from his apprehensions of a sudden march to Philadelphia, he advanced Sullivan's division to Pompton Plains, on the way to Peekskill, and proceeded with the main body of his army to Morristown, thus approaching the Highlands of New York without removing so far from Middlebrook as to be unable to regain that camp should Howe indicate an intention to seize it.
Meanwhile Howe prosecuted diligently his plan of embarkation, which was necessarily attended with circumstances indicating a much longer voyage than one up the North river. These circumstances were immediately communicated to the Eastern States, and Congress was earnestly pressed to strengthen the fortifications on the Delaware, and to increase the obstructions in that river.
In the midst of these appearances certain intelligence was received that Burgoyne was in great force on the lakes, and was advancing against Ticonderoga. This intelligence confirmed the opinion that the main object of Howe must be to effect a junction with Burgoyne on the North river. Under this impression Washington ordered Sullivan to Peekskill, and slowly advanced himself, first to Pompton Plains, and afterward to the Clove, where he determined to remain until the views of the enemy should be disclosed.
While Washington thus anxiously watched the movements of his adversary, an agreeable and unexpected piece of intelligence was received from New England. The command of the British troops in Rhode Island had devolved on General Prescot. Thinking himself perfectly secure in an island, the water surrounding which was believed to be entirely guarded by his cruisers, and at the head of an army greatly superior to any force then collected in that department, he indulged himself in convenient quarters rather distant from camp, and was remiss with respect to the guards about his person. Information of this negligence was communicated to the main, and a plan was formed to surprise him. This spirited enterprise was executed with equal courage and address by Lieutenant-Colonel Barton of the Rhode Island militia.
On the night of the 10th (June, 1777) he embarked on board four whale-boats at Warwick Neck, with a party consisting of about forty persons, including Captains Adams and Philips, and several other officers. After proceeding about ten miles by water unobserved by the British guard boats, although several ships of war lay in that quarter, he landed on the west of the island, about midway between Newport and Bristol Ferry, and marching a mile to the quarters of Prescot, dexterously seized the sentinel at his door, and one of his aids. The general himself was taken out of bed and conveyed to a place of safety.
The success of this intrepid enterprise diffused the more joy throughout America, because it was supposed to secure the liberation of General Lee by enabling Washington to offer an officer of equal rank in exchange for him.
Congress expressed a high sense of the gallant conduct of Colonel Barton and his party, and presented him with a sword as a mark of approbation.
As the fleet fell down toward Sandy Hook, Washington withdrew slowly from the Clove, and disposed his army in different divisions, so as to march to any point which might be attacked.
At length the embarkation was completed and the fleet put to sea. Still, its destination was uncertain. It might be going to the south, or it might return to New York and ascend the Hudson. Soon, however, Washington received intelligence that it had been seen off the capes of the Delaware. It was of course expected to come up the Delaware and attack Philadelphia.
Washington ordered the army to march to Germantown, and himself hastened forward to Chester. The fleet of the British had disappeared again. It might have returned to New York, or it might have sailed to New England, with a view to joining Burgoyne as he was advancing on Ticonderoga.