UAL used to use there 747-100/200 to do most of the routes to Heathrow along with the 767. The 777 has primarily taken over the carriers routes to Heathrow. United's 747-100/200s now ply such routes as Los Angeles-Hong Kong, Los Angeles-Sydney, Chicago-Hong Kong, or Chicago-Honolulu along with their newer 747-400s.
"History does not long entrust the care of freedom to the weak or timid." D. Eisenhower