when did the british army got final defeat against the united state of america
American Revolutionary War Cornwallis made no attempt to break out and engage the Franco-American army before it had established siege works, expecting that reinforcements would arrive from New York, and the Franco-American army laid siege to Yorktown on September 28.[339] Cornwallis continued to think that relief was imminent from Clinton, and he abandoned his outer defenses which were immediately occupied by American troopsâ€”serving to hasten his subsequent defeat.[340] The British then failed in an attempt to break out of the siege across the river at Gloucester Point when a storm hit.[341] Cornwallis and his subordinates were under increasing bombardment and facing dwindling supplies; they agreed that their situation was untenable and negotiated a surrender on October 17, 1781,[342] and 7,685 soldiers became prisoners of the Americans.[343] The same day as the surrender, 6,000 troops under Clinton had departed New York, sailing to relieve Yorktown.[344][345]