The events happened on 22nd April are :



1500 : Sighting of South America : On this day in 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.



1994 : Former U.S. president Richard M. Nixon died.



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.



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



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.



21st April | 23rd April