Victories in the NW Territory by this brother of an explorer forced Britain to surrender the area in 1783
George Rogers 
Clark (November 19, 1752  February 13, 1818) was a surveyor, soldier, and ... 
Because the British ceded the entire Northwest Territory to the United States... [DOC] [TLE] George Rogers Clark - Military Leader, Explorer - Biography.com [PAR] Apr 2, 2014 ... George Rogers Clark fought on the northwest frontier during the Revolutionary 
War, achieving remarkable victories that helped America expand its borders.