Richard Nixon told the American public in a televised address that he would resign the presidency the next day, the first U.S. president ever to do so.

Portugal formally recognized the independence of Guinea-Bissau, ending centuries of colonial rule after a grinding anti-colonial guerrilla war.

Paleoanthropologist Donald Johanson and student Tom Gray discover the 3.2-million-year-old hominin skeleton nicknamed 'Lucy' in Ethiopia's Afar region.

NASA's Mariner 10 probe makes its historic first flyby of Mercury, returning humanity's first close-up images of the solar system's innermost planet.

Paleoanthropologist Donald Johanson found a 3.2-million-year-old hominid skeleton in Ethiopia's Afar region, later named Lucy.

Engineers at Xerox PARC continued refining the Alto personal computer's bitmap display and mouse-driven interface, technology that would later define modern computing.