US Airlines History outlines the development of the commercial airline industry in the United States over several parts: Part 1 discusses the early history including the Wright brothers' first flight in 1903, the growth of air mail services in the 1920s-1930s which led to the establishment of the first major airlines like United, Eastern, and Pan Am. Part 2 covers the introduction of government regulation of the industry through the establishment of the Civil Aeronautics Board (CAB) to regulate fares and entry/exit to routes. Part 3 notes the transition to jet aircraft in the 1950s with planes like the Boeing 707 and the start of non-stop transcontinental flights, but also the issue of half