- Mar 2 Dutch Socialists demand drastic disarmament
- Mar 2 Japan's House of Representatives recognizes male suffrage
- Mar 2 Nationwide road numbering system & US shield marker adopted
- Mar 2 SDAP-Second-Faction of parliament demands drastic disarmament
- Mar 4 Swain's Island, a remote coral atoll, is annexed by the United States and incorporated into American Samoa
- Mar 4 US President Coolidge's inauguration broadcast live on 21 radio stations
- Mar 6 Belgium annexes Eupen, Malmö dy & Sankt Vith
- Mar 7 American Negro Congress organizes
- Mar 9 Pink's War, the first RAF operation conducted independently of the Army or Navy, begins
1st Flight Over Mt Demawend
Mar 10 Walter Mittelholzer is 1st to fly over Mount Demawend in Iran
British Refuse Geneva Agreement
Mar 12 British government of Stanley Baldwin refuses to ratify Geneva agreement
- Mar 13 NHL Championship: Montreal Canadiens sweep Toronto Arenas in 2 games
- Mar 13 Tennessee makes it unlawful to teach evolution
Roncalli Made Bishop
Mar 19 Angelo Giuseppe Roncalli (future Pope John XXIII) becomes a bishop, appointed as Apostolic Visitor to Bulgaria
- Mar 21 Edinburgh's Murreyfield Stadium officially opens
- Mar 21 Iran adopts Khorshidi solar Hijri calendar
- Mar 21 Tennessee governor Austin Peay passes the "Butler Act," making Tennessee the 1st state to outlaw teaching the theory of evolution (repealed 1967)
- Mar 24 KSL-AM in Salt Lake City UT begins radio transmissions
- Mar 27 84th Grand National: Major John Wilson wins aboard 100/9 shot Double Chance; first year a tape, known then as a 'gate', used at the start line
- Mar 30 Stanley Cup Final, Patrick Arena, Victoria, BC: Victoria Cougars (WCHL) beat Montreal Canadiens (NHL), 6-1 for a 3-1 series win; last non-NHL team to win trophy
- Mar 31 WOWO-AM, Ft Wayne Indiana begins radio transmission (500 watts)
Authors
Civil Rights Activists
Inventors
Kings
Revolutionaries
Scientists