Washington had crossed the Delaware River in 1776, December 25th. He was soon to achieve victory in one of the biggest comebacks a war has ever seen. His army advanced southward for Trenton after landing from his 10 day crossing.
Washington would defeat the Prussian/German mercenaries at Trenton. He would withdraw from Trenton, returning a week later to bait British forces southward into Trenton. His plan was soon to be executed as he moved for Princeton
Washington then went on to capture Princeton after British forces were baited out. He pushed the British forces out of most of New Jersey, assuring his control over the state. This greatly unified the American and French militas, and without this victory the war would've never been won.