If it was deemed too hazardous to attack the strong camp at Middlebrook, an attempt to cross the Delaware in the face of an army collected on its western bank, while that under Washington remained unbroken in his rear, was an experiment of equal danger. It suited the cautious temper of Howe to devise some other plan of operation to which he might resort should he be unable to seduce Washington from his advantageous position.
The two great bays of Delaware and Chesapeake suggested the alternative of proceeding by water, should he be unable to maneuver Washington out of his present encampment.
The plan of the campaign being settled and some small reinforcements with the expected camp equipage being received from Europe, Howe, leaving a garrison in New York and a guard in Amboy, assembled his army at Brunswick, and gave strong indications of an intention to penetrate through the country to the Delaware and reach Philadelphia by land.
Believing this to be his real design Washington (June 13, 1777) placed a select corps of riflemen under the command of Colonel Morgan, who had distinguished himself in the unfortunate attempt to storm Quebec, and in whom those particular qualities which fit a man for the command of a partisan corps, designed to act on the lines of a formidable enemy, were eminently united.
He was ordered to take post at Vanvighton's bridge on the Raritan, just above its confluence with the Millstone river, to watch the left flank of the British army and seize every occasion to harass it.
Early in the morning of the 14th, Howe, leaving 2,000 men under the command of General Matthews at Brunswick, advanced in two columns toward the Delaware. The front of the first, under Cornwallis, reached Somerset Court House, nine miles from Brunswick, by the appearance of day, and the second, commanded by General de Heister, reached Middlebush about the same time.
This movement was made with the view of inducing Washington to quit his fortified camp and approach the Delaware, in which event, Howe expected to bring on an engagement on ground less disadvantageous than that now occupied by the American army. But Washington understood the importance of his position too well to abandon it.
On the first intelligence that the enemy was in motion, he drew out his whole army, and formed it to great advantage on the heights in front of his camp. This position was constantly maintained. The troops remained in order of battle during the day, and in the night slept on the ground to be defended.
In the meantime the Jersey militia, with alacrity theretofore unexampled in that State, took the field in great numbers. They principally joined General Sullivan, who had retired from Princeton, behind the Sourland hills toward Flemington, where an army of some extent was forming, which could readily cooperate with that under the immediate inspection of Washington.
The settled purpose of Washington was to defend his camp, but not to hazard a general action on other ground. He had therefore determined not to advance from the heights he occupied into the open country, either towards the enemy or the Delaware.