Mar 11 The Flagstaff War: In New Zealand, Chiefs Hone Heke and Kawiti lead 700 Māoris to chop down the British flagpole and drive settlers out of the British colonial settlement of Kororareka because of breaches of the 1840 Treaty of Waitangi.
- Mar 14 -5.3°F (-20.7°C) in Groningen
- Mar 17 Bristol man Henry Jones patents self-raising flour
- Mar 17 Rubber band patented by Stephen Perry of London
- Mar 26 Joseph Francis, NYC, patents a corrugated sheet-iron lifeboat
- Mar 26 Patent awarded for adhesive medicated plaster, precusor of bandaid
- Mar 28 Mexico drops diplomatic relations with US
- Mar 18 John Chapman, [Johnny Appleseed], American pioneer agronomist dies in Allen County Indiana