Convinced he could build a better plane than those currently in the air, Boeing enlisted his engineering friend, George Conrad Westervelt, to design and build the B&W, a twin-float seaplane. Encouraged by this first effort, Boeing decided to begin his own plane-building company, Pacific Aero Products. He renamed it the Boeing Airplane Company the following year.

In 1919, Boeing, right, flew with Eddie Hubbard and established the first international air mail route.

In 1917, Boeing knew the Navy needed planes for WWI. Betting that his Model C seaplane just might be what they needed, he had the plane shipped off in pieces to Florida and reassembled for Navy officials to test. Boeing's hunch paid off - his company received an order for 50 of the planes. When WWI ended, however, the military drastically cut back its request for new planes. He kept his company afloat by building bedroom furniture, cabinets, and boats. Boeing persevered in the plane-building business, though. He produced a commercial bi-plane, the B-1, which made history March 3, 1919 when Boeing and pilot Eddie Hubbard flew the plane between Seattle and Vancouver, establishing the first international air mail route. The two men ran the route into the mid-1920s.

Boeing outbid the other airlines in 1927 to win a contract to deliver air mail between San Francisco and Chicago. To keep up with the demands of handling air mail, Boeing built the new 40-A transport planes and formed Boeing Air Transport (BAT). BAT proved itself extremely successful. Under his vision and guidance, Boeing's small company had grown by the late 1920s into a thriving business. In addition to Boeing's transportation service, the company by now included divisions for manufacturing planes, engines and propellers

In 1934, the Roosevelt Administration passed new federal antitrust laws which forbid air mail carriers and aircraft manufacturers to be part of the same company. Boeing's air mail contracts were cancelled and he was forced to split his business into several different companies. Later that year, Boeing sold all his stock in the company, but he never lost his enthusiasm for planes. He later volunteered his time as a consultant to Boeing during WWII. He began a very successful thoroughbred-breeding business, among many subsequent ventures. By the time he passed away in 1956, his company had grown into a major aircraft manufacturer about to enter the jet age.