The object of Howe was, by acting on his anxiety for Philadelphia, to seduce him from the strong ground about Middlebrook, and tempt him to approach the Delaware in the hope of defending its passage. Should he succeed in this, he had little doubt of being able to bring on an engagement, in which he counted with certainty on victory.
The considerations which restrained Howe from attempting to march through Jersey, leaving the American army in full force in his rear, had determined Washington to allow him to proceed to the Delaware, if such should be his intention. In that event, he had determined to throw those impediments only in the way of the hostile army which might harass and retard its march, and maintaining the high and secure grounds north of the road to be taken by the enemy, to watch for an opportunity of striking some important blow with manifest advantage.
Washington was not long in penetrating Howe's designs. "The views of the enemy," he writes to General Arnold in a letter of the 17th (June, 1777), "must be to destroy this army and get possession of Philadelphia. I am, however, clearly of opinion, that they will not move that way until they have endeavored to give a severe blow to this army. The risk would be too great to attempt to cross a river when they must expect to meet a formidable opposition in front and would have such a force as ours in their rear. They might possibly be successful, but the probability would be infinitely against them. Should they be imprudent enough to make the attempt, I shall keep close upon their heels and will do everything in my power to make the project fatal to them."
"But, besides the argument in favor of their intending, in the first place, a stroke at this army, drawn from the policy of the measure, every appearance contributes to conform the opinion. Had their design been for the Delaware in the first instance, they would probably have made a secret, rapid march for it, and not have halted so as to awaken our attention, and give us time to prepare for obstructing them. Instead of that they have only advanced to a position necessary to facilitate an attack on our right, the part in which we are most exposed. In addition to this circumstance, they have come out as light as possible, leaving all their baggage, provisions, boas, and bridges at Brunswick. This plainly contradicts the idea of their intending to push for the Delaware."
Finding the American army could not be drawn from its strong position Howe determined to waste no more time in threatening Philadelphia by land, but to withdraw from Jersey and to embark his army as expeditiously as possible for the Chesapeake or the Delaware. On the night of the 19th of June (1777), he returned to Brunswick, and on the 22d to Amboy, from which place the heavy baggage and a few of his troops passed into Staten Island on the bridge which had been designed for the Delaware. {2}
Washington had expected this movement from Brunswick and had made arrangements to derive some advantage from it. General Greene was detached with three brigades to annoy the British rear, and Sullivan and Maxwell were ordered to cooperate with him. In the meantime the army paraded on the Heights of Middlebrook, ready to act as circumstances might require.
About sunrise, Colonel Morgan drove in a picket-guard, soon after which that division commenced its march to Amboy. Some sharp skirmishing took place between this party and Morgan's regiment, but the hope of gaining any important advantage was entirely disappointed, and the retreat to Amboy was effected with inconsiderable loss.
In order to cover his light parties, which still hung on the British flank and rear, Washington advanced six or seven miles to Quibbletown on the road to Amboy, and Lord Stirling's division was pushed still further, to the neighborhood of the Metucking Meeting House, for the purpose of co-operating with the light parties should the retreat to Staten Island afford an opportunity of striking at the rear.
Believing it now practicable to bring on an engagement and probably hoping to turn the left of the American army and gain the heights in its rear, Howe, in the night of the 25th, recalled the troops from Staten Island, and early next morning (June 26, 1777) made a rapid movement in two columns, towards Westfield. The right, under the command of Cornwallis took the route by Woodbridge to the Scotch plains, and the left, led by Howe in person, marched by Metucking Meeting House to fall into the rear of the right column. It was intended that the left should take a separate road soon after this junction and attack the left flank of the American army at Quibbletown, while Cornwallis should gain the heights on the left of the camp at Middlebrook. Four battalions with six pieces of cannon were detached to Bonhamtown.
About Woodbridge the right column fell in with one of the American parties of observation, which gave notice of this movement. Washington discerned his danger, put the whole army instantly in motion, and regained the camp at Middlebrook. Cornwallis fell in with Lord Stirling and a sharp skirmish ensued, in which the Americans were driven from their ground with the loss of three field-pieces and a few men. They retreated to the hills about the Scotch Plains and were pursued as far as Westfield. Perceiving the passes in the mountains on the left of the American camp to be guarded, and the object of this skilful maneuver to be, consequently, unattainable, Cornwallis returned through Rahway to Amboy, and the whole army crossed over to Staten Island. Washington was now again left to his conjectures respecting the plan of the campaign. The very next day (June 27), after Howe had finally evacuated the Jerseys, intelligence was received of the appearance of Burgoyne on Lake Champlain, and that Ticonderoga was threatened. This intelligence strengthened the opinion that the design of Howe must be to seize the passes in the mountains on the Hudson, secure the command of that river, and effect a junction between the two armies. Yet Washington could not permit himself to yield so entirely to this impression, as to make a movement which might open the way by land to Philadelphia. His army, therefore, maintained its station at Middlebrook, but arrangements were made to repel any sudden attack on the posts which defended the Hudson.