France's initial military assistance to the American rebels was a disappointment, with defeats at Rhode Island and Savannah. In 1780, France sent Rochambeau and Grasse to help the Americans, along with large land and naval forces. The French expeditionary force arrived in North America in July 1780. The appearance of French fleets in the Caribbean was followed by the capture of a number of the sugar islands, including Tobago and Grenada. In October 1781, the French naval blockade was instrumental in forcing a British army under Cornwallis to surrender at the Siege of Yorktown. When news of this reached London in March 1782, the government of Lord North fell and Great Britain immediately sued for peace terms; however, France delayed the end of the war until September 1783 in the hope of overrunning more British colonies in India and the West Indies.