U.S. planes bomb North Vietnam. North Vietnamese forces take over Saigon. Alan Shepard becomes first American in space. Watergate scandal engulfs Nixon administration. United Nations is officially established.
Communists build wall to divide East and West Berlin.
Mohandas Gandhi begins leading nonviolent reform movement in India. United States withdraws last ground troops from Vietnam. North Atlantic Treaty Organization established. Democrat Franklin D. Roosevelt beats incumbent President Herbert Hoover. Max Planck proposes quantum theory of energy.