Here Washington had erected fortifications which made it at least difficult for a British force to pass up the river.

Moreover in the highlands of northern New Jersey, with headquarters at Morristown, General Sullivan, recently exchanged, and General Gates now had Lee's army and also the remnants of the force driven from Canada.

But in retreating across New Jersey Washington had been forsaken by thousands of men, beguiled in part by the Tory population, discouraged by defeat, and in many cases with the right to go home, since their term of service had expired.

All that remained of Washington's army after the forces of Sullivan and Gates joined him across the Delaware in Pennsylvania, was about four thousand men.
Howe was determined to have Philadelphia as well as New York and could place some reliance on Tory help in Pennsylvania.

He had pursued Washington to the Delaware and would have pushed on across that river had not his alert foe taken care that all the boats should be on the wrong shore.