In 1934, after the Air Mail Act of 1934 stipulated that all existing aviation holding companies had to break up, United Aircraft and Transport Corporation split into its three parts, Boeing, United Aircraft, and United Air Lines. By the time of this split, United Air Lines could boast complete coast-to-coast service across the country, from New York to San Francisco and Los Angeles (with major stops in Salt Lake City, Omaha, Chicago, and Cleveland). Soon after, on March 30, 1933, United took the lead in introducing what many consider the world's first modern civil airliner, the Boeing 247. In June 1933, United began flying coast-to-coast using this aircraft in a flight that lasted just under 20 hours. Within four months, United was operating as many as 11 round trips daily between New York and Chicago.
During World War II, United, like many other airlines, served the war effort. Beginning in May 1942, it began service to Alaska and across the Pacific Ocean. During the war, the airline transported almost 200,000 tons of men and materials over 21 million miles. At the time, United's fleet consisted of a mix of Douglas DC-3 and Boeing 247 aircraft.
The Boeing 247 is considered by many to be the first modern civil airliner
Like its competitors, American Airlines and Transcontinental and Western Air (TWA), in the post-war years, United Airlines set its sights on dominating the country's coast-to-coast routes. United and TWA both inaugurated their post-war transcontinental services on the same date, March 1, 1946, but while TWA did so with the sleek and modern Lockheed Constellation, United continued to use its old DC-4 aircraft. United was a year late in introducing pressurized cabin service using the DC-6; the airline inaugurated its ten-hour coast-to-coast flight (with a single stop at Lincoln, Nebraska) on April 27, 1947. Each of these DC-6 aircraft could carry as many as 52 passengers for daytime service or 24 sleeper-type passengers for night time operations.
United was dealt a temporary blow when all DC-6 aircraft had to be grounded as a result of a fatal crash in 1947, but business improved when an airline known as Western Airlines decided to sell a key route to United that allowed United to begin service on the important New York-Chicago-Los Angeles route on July 17, 1947. Into the 1950s, United used a mixed fleet of Douglas DC-6B, DC-7, and Convair CV-240 aircraft.
United made major investments into cargo service. On December 23, 1940, it began the first all-cargo service in American aviation history by flying freight between New York and Chicago. Over the years, United also attempted several acquisitions, not all of which were successful. In 1942, United merged with a Mexican airline known as Lineas Aereas Mineras S. A. (LAMSA), but in 1952, sold the airline to Mexican investors after incurring losses. United also acquired Catalina Air Transport in 1946, and in June 1961, it purchased Capital Airlines, a major airline that had tried unsuccessfully to break into the group of “Big Four” airlines in the United States. At the time this was the biggest merger in the American domestic aviation industry. As a result, United served 116 cities with a fleet of 267 aircraft.
United was less aggressive than the other major airlines in introducing jet service. United had pinned its hopes on the Douglas DC-8 instead of the Boeing 707, but United had to wait for the DC-8 to become available and ended up beginning its jet service on September 18, 1959, a full eight months after American Airlines. United was, however, one of the few U.S. companies to buy a foreign jet in large numbers—in this case the French Sud-Aviation SE.210 Caravelle, a jet designed for use on shorter routes. United also purchased Boeing's 720; it was in fact, the very first operator of the 720, first flying the jet on July 5, 1960, between Chicago, Denver, and Los Angeles. The similar Boeing 727 was put into operation by United four years later, on February 6, 1964.
United began jet service on September 18, 1959 using the DC-8
Through most of its early history, United Air Lines was led by Bill Patterson, a former accountant, who assumed presidency of the airline in 1933 and remained in that position until 1963. He remained chairman of the airline until 1966. By the time of his departure, he had left the airline in the enviable position of having the highest number of passenger-miles of any U.S. airline—beating out tough contenders such as American, Eastern, and TWA.
United remained the most powerful domestic airline in the United States through the 1970s. The Deregulation Act of 1978 had important implications for United. For example, the airline cut back on its operations where it was no longer profitable. United pulled out of cities such as Chattanooga, Tennessee and Bakersfield, California, that it had previously served. Instead, like the other major airlines, it focused its activities around several major hubs such as Los Angeles, Chicago, and Tokyo. At the same time, like many other airlines, United also expanded into other areas such as computerized reservation systems, hotel chains, and rental car companies. United also entered new markets in the Pacific, Australia, and Europe using a fleet of Boeing 747-400 jumbo jets. The fall of Pan American offered new opportunities for United. In 1991, it was United that bought Pan Am's coveted Heathrow Airport hub in London. United also acquired Pan Am's Latin American routes later that same year, thus becoming one of the most important international airlines in North America.
But the news was not all good for United. By 1992, fuel costs, interest rates, and a recession forced United to sell some its travel subsidiaries and cancel orders for new aircraft. Ultimately, however, United did not suffer the fate of many of its competitors such as Pan Am, Eastern, and TWA, which either collapsed or declined in importance. After the catastrophic bankruptcies of the 1980s and early 1990s, United remained standing as one of the three airlines (along with Delta and American) that dominated the American airline industry. By 1991, the “Big Three” controlled over half the market in the United States.
United was the first airline to introduce Boeing's new 777 airliner, with a flight from Washington, D.C. to London on June 7, 1995. It has also been making major inroads in the international market. In 1997, for example, it partnered itself with Air Canada, Germany's Lufthansa, the Scandinavian Aircraft System (SAS), and Thai International (later joined by Varig of Brazil) to create the Star Alliance to provide a common network of world-spanning routes. United posted several years of profits in the late 1990s but, due to an economic recession in Asia, the airline's growth in profits has slowed. At the turn of the century, United continued to be one of the most important players in domestic commercial aviation.