At which battle did Americans successfully capture all British forces?

The correct answer is the Battle of Yorktown. This battle, fought in 1781, marked a decisive victory for the American forces during the Revolutionary War. General George Washington, along with French allies, laid siege to British General Cornwallis's troops, effectively trapping them. The Americans managed to surround Yorktown, and after several weeks, Cornwallis was compelled to surrender, resulting in the capture of his entire force.

While the Battle of Saratoga is known for being a turning point in the revolution by gaining French support, it did not result in the capture of all British forces. The Battle of Cowpens was indeed a significant victory, but it did not lead to the complete capture of British troops similar to Yorktown. The Battle of Trenton was an important surprise attack that revitalized American morale but also did not involve the capture of an entire British army. Thus, the Battle of Yorktown stands out as the event where Americans successfully captured all British forces.