King George III's British army was forced to evacuate Boston. They headed to New York. General George Washington responded by moving American troops to Long Island, New York and fortifying Brooklyn Heights. Enthusiasm was high as Washington's ranks swelled to nearly 20,000. Before long, hundreds of British ships filled New York's harbor, carrying 32,000 troops. It was one of the largest invasion forces in history to that date. The thousands of wooden masts of the British ships were described as looking like a forest of trees. Washington wrote to his younger brother John Augustine Washington, May 31, 1776: "We expect...