Question: Which airport that is located in Texas and is the largest hub for American Airlines
Context: Lone Star Airlines was an American regional airline that operated both domestic and international flights.  For much of the airline's life its headquarters were located in the Fort Worth Stockyards in Fort Worth, Texas.  The airline's largest hub was located at Dallas-Fort Worth International Airport.  The airline filed for bankruptcy in August, 1998 and was liquidated in October, 1998. Charlotte Douglas International Airport (IATA: CLT, ICAO: KCLT, FAA LID: CLT) is a joint civil-military public international airport located in Charlotte, North Carolina, United States.  Established in 1935 as Charlotte Municipal Airport, in 1954 the airport was renamed Douglas Municipal Airport after former Charlotte mayor Ben Elbert Douglas, Sr. The airport gained its current name in 1982 and, as of September 2017, it is the second largest hub for American Airlines after Dallas/Fort Worth International Airport, with service to 161 domestic and international destinations.  As of 2016 it was the 5th busiest airport in the United States, ranked by passenger traffic and aircraft movements.  It was also the 7th business airport in the world ranked by aircraft movements Charlotte is the largest airport in the United States without any nonstop service to Asia.  The airport serves as a major gateway to the Caribbean Islands.  CLT covers 5,558 acres (2,249 ha) of land. Air Canada is the largest airline and flag carrier of Canada.  Founded in 1936 as Trans-Canada Airlines, it provides scheduled services to 194 destinations on five continents.  Its largest hub is Toronto Pearson International Airport, followed by Montreal-Pierre Elliott Trudeau International Airport, Vancouver International Airport and Calgary International Airport.  Air Canada is the world's 10th largest passenger airline by fleet size, and the airline is a founding member of Star Alliance.  In 2014, Air Canada together with its Air Canada Express regional partners carried over 38 million passengers.  Between them, they operate on average more than 1,500 scheduled flights daily. Dallas/Fort Worth International Airport (IATA: DFW, ICAO: KDFW, FAA LID: DFW) is the primary international airport serving the Dallas–Fort Worth metroplex area in the U.S. state of Texas.  It is the largest hub for American Airlines, which is headquartered near the airport.  2016 was a record year for DFW, as the airport served 65,670,697 passengers. St. Louis Lambert International Airport (IATA: STL, ICAO: KSTL, FAA LID: STL) is an international airport serving Greater St. Louis, Missouri, United States.  It is 14 mi northwest of downtown St. Louis in unincorporated St. Louis County between Berkeley and Bridgeton.  Commonly named Lambert Field, it is the largest and busiest airport in Missouri with 270 daily departures to over 80 domestic and international locations.  In 2016, 13.9 million passengers traveled through the airport.  Lambert-St.  Louis serves as a hub for Air Choice One and Cape Air.  It is a focus city for Southwest Airlines, and was a former hub for Trans World Airlines and later for American Airlines. Speedway Field was the original name for the airfield that was to evolve into Minneapolis-St.  Paul International Airport, the twelfth busiest airport in the United States; it was also the largest hub for Northwest Airlines and the third largest hub for Delta Air Lines, Northwest's successor. Colleyville is an affluent city and suburb of Fort Worth located in northeast Tarrant County, Texas, United States.  Located roughly 3.5 mi from Dallas/Fort Worth International Airport, the population was 22,807 at the 2010 census.  Emerging from a number of small, rural settlements along the Cotton Belt Route, Colleyville was originally known as Bransford when Dr. Lilburn Howard Colley settled there in 1880.  He was a prominent area physician and a veteran of the Union Army.  In 1914 when Walter G. Couch opened a grocery store near Dr. Colley's home the community was renamed Colleyville in his honor. Philadelphia International Airport (IATA: PHL, ICAO: KPHL, FAA LID: PHL) , often referred to just by its IATA code PHL, is a major airport in Philadelphia, Pennsylvania, United States, and is the largest airport in the Delaware Valley region and in the state.  The airport is a major international hub for American Airlines and a regional cargo hub for UPS Airlines.  Philadelphia International Airport is also a focus city for ultra low cost airline Frontier Airlines.  The airport has service to destinations in the United States, Canada, the Caribbean, Latin America, Europe, and the Middle East.  Most of the airport property is located in Philadelphia proper.  The international terminal and the western end of the airfield are located in Tinicum Township, Delaware County.  PHL covers 2,302 acres (932 ha). El Dorado International Airport (IATA: BOG, ICAO: SKBO) is an international airport located in Bogotá, Colombia.  It is ranked among the world's 50 busiest airports in terms of: passenger traffic (ranked third in Latin America with 25,009,483 passengers in 2013), cargo traffic (ranked first in Latin America (33rd worldwide) with 622,145 metric tons in 2013) and traffic movements (ranked second in Latin America (45th worldwide) with 304,330 aircraft movements in 2011).  As such, it is the largest airport in Colombia and the main international and domestic air gateway in the country, serving as the main and largest hub for Avianca (the national flag carrier of Colombia), Copa Airlines Colombia, LATAM, Satena, EasyFly and other cargo companies.  It is managed by Operadora Aeroportuaria Internacional (OPAIN), a consortium composed of Colombian construction and engineering firms and the Swiss company Flughafen Zürich AG. American Eagle is an American brand name for the regional branch of American Airlines, under which ten individual regional airlines operate short- and medium-haul feeder flights.  Three of these airlines, Envoy Air (formerly American Eagle Airlines), Piedmont Airlines and PSA Airlines, are wholly owned subsidiaries of American Airlines Group.  Just like the regional brands of the other two major airlines (Delta Connection and United Express), American Airlines' regional brand accounts for more than 60% of American Airlines flights.
Answer: Dallas/Fort Worth International Airport