Final answer:
The Battle of Trenton and the Battle of Princeton were the two surprise victories by the American Continental Army, achieved under the leadership of General George Washington during the winter of 1776-1777.
Step-by-step explanation:
Surprise American Victories During the Revolutionary War
The two battles that were considered surprise victories by the American Continental Army were the Battle of Trenton and the Battle of Princeton. During the winter of 1776-1777, General George Washington went against conventional 18th-century military tactics by launching attacks in the winter season. On December 25, 1776, Washington and his army crossed the Delaware River and achieved an astonishing victory at Trenton by defeating the Hessians. Not long after, on January 3, 1777, Washington continued his unconventional actions with another unexpected victory at Princeton. These victories played a crucial role in boosting the morale of the Continental Army and laid the groundwork for future successes against the British forces.