First supersonic flight

According to Official Guinness Records,

The first ever supersonic flight was achieved on 14 October 1947 by Captain (later Brigadier General) Charles `Chuck' Elwood Yeager (USA), over Lake Muroc, California, USA, in a Bell XS-1 rocket aircraft. Yeager reached Mach 1.015 (1078 km/h 670 mph) at an altitude of 12,800 m (42,000 ft). The XS-1 is in the Smithsonian Institution, Washington, DC, USA.

For a complete list of 1947 records, please visit 1947 Guinness Records in United States.

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