Following airline deregulation, American Airlines (which had already been one of the largest carriers serving the Dallas/Fort Worth area for many years) established its first hub at DFW on June 11, 1981. American finished moving its headquarters from Grand Prairie, Texas, to a building in Fort Worth located on the site of the old Greater Southwest International Airport, near DFW Airport on January 17, 1983; the airline began leasing the facility from the airport, which owns the facility. By 1984, the American hub occupied most of Terminal 3E and part of Terminal 2E. American's hub grew to fill all of Terminal 2E by 1991. American also began long-haul international service from DFW, adding flights to London in 1982 and Tokyo in 1987.