Wikipedia:Selected anniversaries/April 22
April 22: Earth Day in the United States (1970)
- 1500 - Portuguese explorer Pedro Álvares Cabral and his crew became the first Europeans to sight Brazil.
- 1836 - After losing the Battle of San Jacinto, Mexican General Antonio López de Santa Anna was captured and forced to allow Texan independence.
- 1913 - The Bolshevik newspaper Pravda was first published in Saint Petersburg, Russia.
- 1914 - Babe Ruth played his first professional baseball game as a pitcher for the Baltimore Orioles.
- 1915 - Chlorine gas was released as a chemical weapon in the Second Battle of Ypres, the first large-scale use of poison gas in World War I.