Today in History: April 22

2000: Armed immigration agents took Elian Gonzalez from the Miami home of his relatives to reunite him with his father.

1994: Former U.S. president Richard M. Nixon died at the age 81.

1970: First celebrated on this day in 1970 in the U.S., Earth Day—founded by American politician and conservationist Gaylord Anton Nelson—helped spark the environmental movement and quickly grew into an international event.

1915: During World War I, German forces introduced the systematized use of chemical warfare when they released chlorine gas along a 4-mile (6-km) front at the Second Battle of Ypres.

1889: At noon, by federal decree, white settlers were allowed into Indian Territory, sparking a land rush involving tens of thousands in what became Oklahoma Territory.

1870: Vladimir Ilich Lenin—who founded the Bolshevik political faction (1912–17), inspired and led the Bolshevik Revolution (1917), headed (1917–24) the Soviet state, and founded the organization known as the Comintern (Communist International)—was born.

1864: Congress authorized the inscription "In God We Trust" on coins minted as U.S. currency.

1724: German philosopher Immanuel Kant was born in Königsberg, Prussia (now Kaliningrad, Russia).

1616: The Spanish poet Cervantes died in Madrid. (Some sources say April 23.)

1509: Henry VIII became king of England.

1500: Portuguese explorer Pedro Álvares Cabral, while on a voyage tracing Vasco da Gama's 1497–99 water route to India, sighted the mainland of South America near the present-day city of Pôrto Seguro, Brazil.

1370: Construction began on the Bastille, the medieval fortress that came to symbolize French despotism.

1073: Gregory VII (later canonized) was elected by acclamation to succeed Alexander II as pope.