Answer: They were able to regain combat morale.
Step-by-step explanation:
The battle of Trenton came after a series of failures by the Washington Army. On the Christmas Eve of 1776, Washington assembled its troops and crossed the Delaware River in New Jersey. As the British ended their military campaign for that year, they were preparing for the winter.
At Hassen in Trenton, they left a garrison filled with rental troops. Washington completely surprised them and captured over 1000 mercenaries. This significantly raised the morale of the US military.