August 27, 1775.
The Battle of Brooklyn.
A British victory was almost inevitable. George Washington was defending a city built on islands (Long Island, Manhattan Island, Staten Island) and his attacker had command of the waterways between the islands. The British had learned at Bunker Hill not to underestimate the American ability to withstand a frontal assault, and had won a maneuver victory by attacking the American flank after a night march. But perhaps the British had learned too much caution at Bunker Hill, or perhaps General William Howe was too sympathetic to the Americans, and thought wiping out Washington's army would make a settlement with the rebels impossible. For whatever the reason, the British had an opportunity this day to largely destroy the American army and they let them escape.
Winston Churchill once wrote about an admiral (Admiral Beatty in WWI) that he was the only person who could have lost the war in an afternoon. Was William Howe the general who could have won the American Revolution for King George in an afternoon, and let it go?