First to 10k posts

General Lon Nol ousts Prince Norodom Sihanouk of Cambodia.

March 18 - United States Postal Service workers in New York City go on strike; the strike spreads to the state of California and the cities of Akron, Ohio, Philadelphia, Pennsylvania, Chicago, Boston, and Denver, Colorado; 210,000 out of 750,000 U.S. postal employees walk out. President Nixon assigns military units to New York City post offices. The strike lasts 2 weeks.

March 21 - The first Earth Day proclamation is issued by San Francisco Mayor Joseph Alioto.

March 21 - "All Kinds of Everything" sung by Dana (music and text by Derry Lindsay and Jackie Smith) wins Eurovision Song Contest 1970 for Ireland.

March 25 - The Concorde makes its first supersonic flight (700 mph/1127 km/h).

March 31 - NASA's Explorer 1, the first American satellite and Explorer program spacecraft, reenters Earth's atmosphere after 12 years in orbit.

March 31 - Japan Airlines Flight 351, carrying 131 passengers and 7 crews from Tokyo to Fukuoka, is hijacked by Japanese Red Army members. All passengers are eventually freed.

April 1 - President Richard Nixon signs the Public Health Cigarette Smoking Act into law, banning cigarette television advertisements in the United States, starting on January 1, 1971.

April 1 - American Motors Corporation introduces the Gremlin.

April 8 - A huge gas explosion at a subway construction site in Osaka, Japan kills 79 and injures over 400.