They fled British from New York and crossed in to PA. Fearing the solders would leave due to lack of supplies. Washington planned a surprise attack on the Hessians in Trenton NJ.
Washington's 2,000 soldiers crossed the Delaware River at night, marched 10 miles, and attacked the Hessians at 8:00 in the morning. The Americans defeated the approximately 1,500 force, capturing 900 soliders and their supplies without suffering a single casualty durning the battle. Washington Quickly gathered supplies and had them march back across the river to PA.