The force brought into the field by the United States required all the aid which could be derived from strong positions and unremitting vigilance. On the 20th of May (1777) the army in Jersey, excluding cavalry and artillery, amounted to only 8,378 men, of whom upwards of 2,000 were sick. The effective rank and file were only 5,738. Had this army been composed of the best disciplined troops, its inferiority in point of numbers must have limited its operations to defensive war, and have rendered it incompetent to the protection of any place whose defense would require a battle in the open field. But more than half the troops were unacquainted with the first rudiments of military duty, and had never looked an enemy in the face. As an additional cause of apprehension, a large proportion of the soldiers, especially from the middle States, were foreigners, in whose attachment to the American cause full confidence could not be placed. Washington, anticipating a movement by land toward Philadelphia, had taken the precaution to give orders for assembling on the western bank of the Delaware an army of militia strengthened by a few Continental troops, the command of which was given to General Arnold who was then in Philadelphia employed in the settlement of his accounts. The first and real object of the campaign on the part of Howe was the acquisition of Philadelphia. He intended to march through Jersey, and after securing the submission of that State to cross the Delaware on a portable bridge constructed in the winter for the purpose and proceed by land to that city. If, in the execution of this plan, the Americans could be brought to a general action on equal ground, the advantages of the royal army must insure a victory. But should Washington decline an engagement and be again pressed over the Delaware the object would be as certainly obtained. Had Howe taken the field before the Continental troops were assembled this plan might probably have been executed without any serious obstruction, but the tents and camp equipage expected from Europe did not arrive until Washington had collected his forces and taken possession of the strong post on the Heights of Middlebrook. It would be dangerous to attack him on such advantageous ground, for, although his camp might be forced, victory would probably be attended with such loss as to disable the victor from reaping its fruits. 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.