On this day in history March 21,
- 1970 – The first Earth Day proclamation is issued by Mayor of San Francisco Joseph Alioto.
- 1980 – US President Jimmy Carter announces a United States boycott of the 1980 Summer Olympics in Moscow to protest the Soviet war in Afghanistan.
- 1980 – Dallas aired its “A House Divided” episode, which led to eight months of international intrigue regarding Who shot J.R.?
- 1986 – Debi Thomas became the first African-American to win the World Figure Skating Championship
- 1989 – Sports Illustrated reports allegations tying baseball player Pete Rose to baseball gambling.
- 1990 – Namibia becomes independent after 75 years of South African rule.
- 1999 – Bertrand Piccard and Brian Jones become the first to circumnavigate the Earth in a hot air balloon.