Task: Question Understanding
Input (English): Passage: When Major General Nathanael Greene took command in the South, Marion and Lieutenant Colonel Henry Lee were ordered in January 1781, to attack Georgetown but were unsuccessful. In April they took Fort Watson and in May they captured Fort Motte, and succeeded in breaking communications between the British posts in the Carolinas. On August 31, Marion rescued a small American force trapped by 500 British soldiers, under the leadership of Major C. Fraser. For this action he received the thanks of the Continental Congress. Marion commanded the right wing under General Greene at the Battle of Eutaw Springs. In January 1782, he was elected to a new State Assembly at Jacksonborough and left his troops to take up his seat. During his absence his brigade grew disheartened, particularly after a British sortie from Charleston, and there was reportedly a conspiracy to turn him over to the British. But in June of that year, he put down a Loyalist uprising on the banks of the Pee Dee River. In August he left his brigade and returned to his plantation. In 1782, the British Parliament suspended offensive operations in America, and in December 1782, the British withdrew their garrison from Charleston. The war was brought to an end by the Treaty of Paris.
Question: When did Marion rescue the American force?
Output (English): date