The expedition, 5,500 strong, arrived in America in July 11, 1780. A second wave of 2,500 was intended to join them but was unable to escape the British blockade of Brest. After remaining inactive for almost a year, Rochambeau marched his troops south to rendezvous with George Washington's Continental Army for a planned attack on New York City. At Rochambeau's urging, Washington abandoned the planned attack and instead they moved into Virginia to join with the French fleet of Admiral François de Grasse to trap Lord Cornwallis's British army at Yorktown, forcing its surrender in October 1781.