- 1821 First revolutionary act in Monastery of Agia Lavra, Kalavryta, Greek War of Independence.
- 1865 Battle of Bentonville ends, last Confederate effort to stop Sherman
- 1918 During WW I Germany launches Somme offensive
- 1922 KGW-AM in Portland OR begins radio transmissions
- 1942 Convoy QP9 departs Great Britain to Murmansk
- 1945 During WW II Allied bombers begin 4-day raid over Germany
- 1958 USSR performs atmospheric nuclear test
21st March in History