Aviation can be divided into military aviation, air transport (commercial airline operations), and general aviation (agricultural, business, charter, instructional, and pleasure flying). The first successful flights of a motor-powered airplane carrying a human were made by Orville and Wilbur Wright near Kitty Hawk, N.C. on Dec. 17, 1903. The first successful seaplane was constructed in 1911-12. During the early 1900s, aviators demonstrated the feasibility of air travel to various parts of the world. World War I provided additional motivation for aviation research and development.
The availability of cheap, surplus aircraft in the U.S. after the war encouraged barnstorming and stunt-flying; the result was a more airplane-conscious public. Private companies in America contracted the carrying of airmail after 1925. Technological improvements in wind tunnel testing, engine and airframe design, and maintenance equipment combined in the 1930s to provide faster, larger, and more durable airplanes. The transportation of passengers became profitable, and routes were extended to include several foreign countries. Transpacific airmail service began in 1934, and was soon followed by a similar service for passengers. In 1939 the first transatlantic service for mail and passengers was inaugurated. The application of jet propulsion to commercial air transportation began in 1952. The first supersonic transports (SST) for passenger service were put into service during the mid-1970s, but commercial aviation was transformed by jumbo jetliners that carry hundreds of passengers on a single flight.