United Airlines Boeing 247-D

In 1933, United Airlines bought the first Boeing 247-D.  This two-motor airliner could fly at 200 miles per hour, speeding up transcontinental flights and urging other aircraft manufacturers to build even faster planes.  United's 247-D placed third in the 1934 England-Australia air race, and is on display at the Smithsonian under a Douglas DC-3.