The maneuver was simple enough.

Instead of taking the obvious course of again retreating across the Delaware Washington decided to advance, to get in behind Cornwallis, to try to cut his communications, to threaten the British base of supply and then, if a superior force came up, to retreat into the highlands of New Jersey.

There he could keep an unbroken line as far east as the Hudson, menace the British in New Jersey, and probably force them to withdraw to the safety of New York.
All through the night of January 2, 1777, Washington's camp fires burned brightly and the British outposts could hear the sound of voices and of the spade and pickaxe busy in throwing up entrenchments.

The fires died down towards morning and the British awoke to find the enemy camp deserted.

Washington had carried his whole army by a roundabout route to the Princeton road and now stood between Cornwallis and his base.