President Truman seizes steel mills to prevent a strike by 600,000 CIO steelworkers. The Supreme Court rules the seizure is unconstitutional because the President did not have approval from Congress. The steelworkers go on strike, which is later settled by negotiations. Also that year:

_ King George VI of England dies and is succeeded by his daughter Queen Elizabeth II.

_ Edward Teller successfully tests a hydrogen bomb, the world’s first thermonuclear weapon.