FM 1171 was first designated on March 30, 1949 from proposed US 77 west  to a county road; at that time, the Lewisville area was undeveloped, and current alignment of  US 77 (now superseded by the Interstate 35E freeway) had yet to be constructed.
FM 1171 was first established on March 30, 1949, from proposed US 77 west to a county road; at that time, the Lewisville area was unoccupied and undeveloped, and the current route of US 77 (now replaced by Interstate 35E) had not yet been constructed.