The 707 began as a discussion and some sketches in 1949 when Boeing engineers Ed Wells, George Schairer and John Alexander began thinking about a swept-wing jet airliner. Boeing was an innovative company and its military aircraft were second to none. Ed Wells, for example, appointed Boeing's chief engineer in 1943, had worked on the design of the famous B-17 Flying Fortress bomber of which 12,731 were built. Boeing's subsequent B-29 Superfortress, B-47 Stratojet and B-52 Stratofortress bombers were all aviation milestones and commercially successful. In the field of civil aviation, however, Boeing played a very junior fiddle to its rivals Douglas, of DC-3 or 'Dakota' fame, and Lockheed, with its pre-war Electra and post-war Constellation. In fact, Boeing had lost money on virtually all its airliners including its latest, and last, piston-engine design, the 377 Stratocruiser of which just 46 were built for a deficit of $13.5m.
I stumbled across an interesting article on the Boeing 707 this morning.