On October 14, 1947, the first manned supersonic flight took place. General (then Captain) Charles Elwood “Chuck” Yeager flew the Bell X-1, christened “Glamorous Glennis” after his wife, past the speed of sound. The plane was launched from the belly of a specially modified Boeing B-29 Superfortress and reached a speed of 700 miles per hour, Mach 1.06, at an altitude of 13,000 meters. Consequently, the National Aeronautic Association awarded the prestigious Collier Trophy for the year 1947 to the three main participants in the program. Lawrence Dale “Larry” Bell of Bell Aircraft, John Stack of the National Advisory Committee for Aeronautics (NACA) and General Yeager were honored by President Harry S. Truman at the White House.

The Bell X-1,, originally designated XS-1, was the result of a cooperative program initiated in 1944 by NACA and the US Army Air Forces. On March 16, 1945, Bell Aircraft Corporation was awarded a contract to develop three transonic and supersonic research aircraft, and the company built three rocket-powered XS-1s. The XS-1 was the first high-speed aircraft built purely for aviation research purposes and was never intended for production. It was also the first of the X-planes, a series of experimental US aircraft used for testing of new technologies and usually kept highly secret during development.