American Airlines was formed through the merger of 80 carriers in 1930. Since then, American has completed several major mergers with other carriers including Trans Caribbean Airways in 1971, Air California in 1987, Reno Air in 1999, Trans World Airlines (TWA) in 2001, and US Airways in 2013.

Predecessors American Airlines' earliest predecessor company to commence operations was Robertson Aircraft Corporation, which began mail flights on April 15, 1926.

Early history

American Airlines was developed from a conglomeration of 82 small airlines through acquisitions in 1930 and reorganizations; initially, American Airways was a common brand used by a number of independent carriers. These included Southern Air Transport in Texas, Southern Air Fast Express (SAFE) in the western United States, Universal Aviation in the Midwest (which operated a transcontinental air/rail route in 1929), Thompson Aeronautical Services (which operated a Detroit-Cleveland route beginning in 1929), and Colonial Air Transport in the Northeast. Like many early carriers, American earned its keep carrying U.S. Mail. By 1933, American Airways operated a transcontinental route network serving 72 cities, mostly in the northeastern, midwestern, and southwestern United States.

In 1934, American Airways Company was acquired by E. L. Cord, who renamed it "American Air Lines". Cord hired Texas businessman C. R. Smith to run the company. Smith worked with Donald Douglas to develop the DC-3, which American Airlines was first to fly, in 1936. American's DC-3 made it the first airline to be able to operate a route that could earn a profit solely by transporting passengers; other carriers could not earn a profit without U.S. Mail. With the DC-3, American began calling its aircraft "Flagships" and establishing the Admirals Club for valued passengers. The DC-3s had a four-star "admiral's pennant" outside the cockpit window while the aircraft was parked. American operated daily overnight transcontinental service between New York and Los Angeles through Dallas/Fort Worth and other intermediate stops, advertising the service as an "all-year southern route."

American Airlines was the first to cooperate with Fiorello LaGuardia to build an airport in New York City, and became owner of the world's first airline lounge at the new LaGuardia Airport (LGA), known as the Admirals Club. Membership was initially by invitation only, later changing to an open policy that accepted members who paid dues.

For more than eight decades, American Airlines' "signature" service has been its daily transcontinental flights between New York and Los Angeles designated as #1 (westbound) and #2 (eastbound). While the current 2,500 miles non-stop jet service between John F. Kennedy International Airport (JFK) and Los Angeles International Airport (LAX) averages six hours, in 1939 Flight #1 (which departed from Newark Airport in New Jersey at 7:10 a.m. Eastern Time and terminated at Glendale Airport in suburban Los Angeles at 12:29 am Pacific Time) took 20 hours and 19 minutes to complete, made eight intermediate stops (in Washington, DC; Nashville, TN; Memphis, TN; Dallas, TX; Ft. Worth, TX; El Paso, TX; Tucson, AZ; and Phoenix, AZ), and had a change of planes from a DC-2 to a DC-3 "Flagship Skysleeper" in Memphis. Although on March 1, 1962, Flight #1, operated by a Boeing 707 (N7506A), crashed in Jamaica Bay two minutes after takeoff from Idlewild (now JFK) Airport, killing all 87 passengers and 8 crew on board, American Airlines retained #1 as the flight number of the service instead of retiring it, as is the general practice after a fatal accident.

Post war

After World War II American acquired American Export Airlines, renaming it as American Overseas Airways, to serve Europe. AOA was sold to Pan Am in 1950. AA launched another subsidiary, American Airlines de Mexico S.A., to fly to Mexico and built several airports there. American Airlines provided advertising and free usage of its aircraft in the 1951 film Three Guys Named Mike. Until Capital merged into United in 1961 AA was the largest American airline, which meant second-largest in the world, after Aeroflot.

American Airlines ordered British-built de Havilland Comets; the orders were canceled when the Comets were found to suffer serious metal fatigue. American Airlines introduced transcontinental Boeing 707s on January 25, 1959, and invested $440 million in jet aircraft up to 1962, launched the first electronic booking system, Sabre, with IBM, and built a terminal at Idlewild (now JFK) Airport in New York City, which became the airline's largest base. Vignelli Associates designed the AA eagle logo in 1967. Vignelli attributes the introduction of his firm to American Airlines to Henry Dreyfuss, the legendary AA design consultant. The logo was in use until January 17, 2013.

In 1966, American Airlines published a specification to manufacturers to offer a widebody aircraft smaller than Boeing 747, but capable of flying similar long-range routes from airports with shorter runways. McDonnell Douglas proposed the DC-10 trijet as a response. On February 19, 1968, President of American Airlines George A. Spater, and James S. McDonnell of McDonnell Douglas announced American's intention to acquire the DC-10. American Airlines ordered 25 DC-10s in its first order."American Orders 25 'Airbus' Jets." St. Petersburg Times, September 14, 2011. The DC-10 made its first flight on August 29, 1970, and received its type certificate from the FAA on July 29, 1971. On August 5, 1971, American's DC-10 made the type's first commercial service on a round trip flight between Los Angeles and Chicago. Lockheed Corporation also responded with the L-1011 TriStar, but lost interest from American Airlines due to higher price.

In 1970 American Airlines had flights from St. Louis, Chicago, and New York to Honolulu and on to Sydney and Auckland via American Samoa and Nadi, Fiji. In 1971, American acquired Trans Caribbean Airways. On March 30, 1973, American became the first major airline to employ a female pilot when Bonnie Tiburzi was hired to fly Boeing 727s. American Airlines has been innovative in other aspects, initiating several of the industry's major competitive developments including computer reservations systems, frequent flyer loyalty programs, and two-tier wage scales.

+ Revenue passenger-milesHandbook of Airline Statistics (biannual CAB publication) (millions)+ (Scheduled service only) American Trans Caribbean 1951 2,554 – 1955 4,358 – 1960 6,371 208 1965 9,195 433 1970 16,623 819 1975 20,871 (merged 1971)

American operated a cargo operation called American Freighter until 1984, using cargo-only Boeing 707 and Boeing 747 aircraft that had previously been used in passenger service.

1980s–1990s

After moving its headquarters to Fort Worth, Texas from New York City in 1979, American Airlines changed to a hub-and-spoke system in 1981, opening its first hub at Dallas/Fort Worth International Airport. American opened a second hub in the new Terminal 3 at Chicago O'Hare in 1982, and began transatlantic service between Dallas and London in May 1982. Led by its new chairman and CEO, Robert Crandall, American expanded its service from these hubs through the 1980s, adding service to other European destinations as well as Japan.

In the late 1980s, American Airlines opened three hubs for north–south traffic. San Jose International Airport was added after American purchased AirCal. American built a terminal and runway at Raleigh-Durham International Airport for the growing Research Triangle Park nearby, and to compete with USAir's hub in Charlotte/Douglas International Airport. Nashville International Airport was also added as a hub. American also planned a north–south hub at Stapleton International Airport in Denver during the mid-1980s, but postponed those plans due to the planned development of Denver International Airport.

In 1988, American Airlines acquired a 7.5% stake in Air New Zealand.Qantas group wins ANZ carriers Flight International 7 January 1989 page 18

In 1991, American Airlines bought the assets of TWA's operations at London Heathrow for $445 million. Until open skies came into effect in April 2008, American Airlines and United Airlines were the only U.S. carriers permitted to serve Heathrow.

American took delivery of 19 McDonnell Douglas MD-11 aircraft starting in 1991, aiming to operate long-haul routes such as DFW-Hong Kong. However, the aircraft's performance was disappointing, and American agreed to sell its MD-11 fleet to FedEx in 1995. The following year, American placed what was then the largest aircraft order in history, agreeing to buy up to 630 Boeing aircraft including the Boeing 777 and Boeing 737.

Lower fuel prices and a favorable business climate led to higher profits in the 1990s. The industry's expansion was not lost on pilots who on February 17, 1997, went on strike for higher wages. President Bill Clinton invoked the Railway Labor Act citing economic impact to the United States, quashing the strike. Pilots settled for wages lower than their demands.

The three new hubs were abandoned in the 1990s: some San Jose facilities were sold to Reno Air, and at Raleigh/Durham to Midway Airlines. Midway went out of business in 2003. American Airlines purchased Reno Air in February 1999 and integrated its operations on 31 August 1999, but did not resume hub operations in San Jose. American discontinued most of Reno Air's routes, and sold most of the Reno Air aircraft, as it did with Air California 12 years earlier. The only remaining route from the Air California and Reno Air purchases is from San Francisco to Los Angeles.

During this time, concern over airline bankruptcies and falling stock prices brought a warning from American's CEO Robert Crandall.Petzinger Jr., Thomas (1995). Hard landing. Three River Press, New York, 594 p. . "I've never invested in any airline", Crandall said. "I'm an airline manager. I don't invest in airlines. And I always said to the employees of American, 'This is not an appropriate investment. It's a great place to work and it's a great company that does important work. But airlines are not an investment.'" Crandall noted that since airline deregulation of the 1970s, 150 airlines had gone out of business. "A lot of people came into the airline business. Most of them promptly exited, minus their money," he said.

Miami International Airport became a hub after American Airlines bought Central and South American routes ("El Interamericano") from Eastern Air Lines in 1990 (inherited from Braniff International Airways but originated by Pan American-Grace Airways which was known as Panagra). Through the 1990s, American Airlines expanded its network in Latin America to become the dominant U.S. carrier in the region.

On October 15, 1998, American Airlines became the first airline to offer electronic ticketing in the 44 countries it serves.

In 1999, American Airlines, British Airways, Cathay Pacific, Canadian Airlines, and Qantas founded the global airline alliance Oneworld.

2000s Robert Crandall left in 1998 and was replaced by Donald J. Carty, who negotiated the purchase of the near-bankrupt Trans World Airlines (it would file for its third bankruptcy as part of the purchase agreement) and its hub in St. Louis in April 2001.