American Airlines is based in Dallas (DFW). They also have hubs in Chicago (ORD) - San Jose (SJC) and San Juan (SJU).
American Airlines uses 47 Boeing 777-200
20 are used on the Transatlantic flights to Europe (Their hub in London (LHR))
10 deployed on the South American destinations (Buenos Aires, Sao Paulo, Rio)
9 fly to Asia (Their Tokyo hub, Shanghai, Delhi)
The average daily utilisation of the 777-200 is just over 12 hours.