Dulles International Airport operates on two terminals that have 113 aircraft gates spread across. Terminal 1 Departure Level is for domestic and international flights, while Terminal 2 Arrivals Level is for domestic and international flights also for the passenger that have connecting flights.
Dulles International Airport's Terminal 1 has such domestic airline carriers, such as American, Southwest, Delta, and US Airways. It's made of A, B, C, D, Z and H gate. The building was completed in 1963.