Some airlines have sophisticated web interactive route maps. Sadly, American does not. For airports that don't have vast numbers of AA flights,
www.flightstats.com will do. Click on the 'flight status by airport' tab, enter the airport code, and use the specific airline code: this will give you all arrivals (or departures) by an airline from an airport for a specific date.
GIG Departures: Tue Sep 14, 2010 All day Choose Destination Show Codeshares
Choose Airline
All day
GRU Sao Paulo AA 950 American Airlines 5:55 PM 6:09 PM T-1 En Route
On-time 763
MIA Miami AA 904 American Airlines 8:26 PM 8:56 PM ~ T-1 Scheduled
20 min 763