The sleek, four-engine jet transport was an outgrowth of the development of the KC-135 jet tanker for the U.S. Air Force begun by Boeing in 1951. The plane was officially listed as the 367-80 but became widely known as simply the "Dash-80." The commercial airliner variant, marketed under the company model number "707," flew in 1958.
Although preceded into service by Britain's troubled DeHaviland Comet airliner, the 707 was the first jet transport to win broad public and commercial acceptance and thereby ushered in the modern "Jet Age" of airline travel.
Boeing derived the design from military plans, but financed development with its own funds in a gamble that literally "bet the company" on future sales. The risk began to pay off with the first aircraft sales a year later, and it established Boeing as the world's leader in jet transport manufacture.