The Battle of Long Island on August 27, 1776 saw the British army of 20,000 men, including Hessian soldiers, launch a surprise attack on the Continental Army's forces in New York, led by Generals Washington, Putnam, and Alexander, killing over 300 Americans and capturing around 1,000 due to an unguarded pass that the British learned about; though outnumbered, the Americans were eventually able to retreat under cover of night to Manhattan Island, evacuating 9,000 troops.