Washington made a secret plan to attack Trenton and Princeton to boost troop morale and secure supplies, as the Continental Army was at risk after a difficult winter. On Christmas Eve 1776, Washington and his troops crossed the Delaware River, then surprised and defeated the German forces in Trenton the next day. This victory at Trenton, along with another soon after at Princeton, encouraged more colonists to join the fight for independence, reversing fortunes for the Revolutionary War effort.