What Happened This Day In History... April 20

1139		The Second Lateran Council opens in Rome.
1657		English Admiral Robert Blake fights his last battle when he destroys the Spanish fleet in Santa Cruz Bay.
1769		Ottawa Chief Pontiac is murdered by an Indian in Cahokia.
1770		Captain Cook discovers Australia.
1775		British troops begin the siege of Boston.
1792		France declares war on Austria, Prussia, and Sardinia.
1809		Napoleon defeats Austria at Battle of Abensberg, Bavaria.
1836		The Territory of Wisconsin is created.
1841		Edgar Allen Poe's first detective story is published.
1861		Robert E. Lee resigns from the U.S. Army.
1879		The first mobile home (horse-drawn) is used in a journey from London to Cyprus.
1916		Wrigley Field opens in Chicago.
1919		The Polish Army captures Vilno, Lithuania from the Soviets.
1940		The first electron microscope is demonstrated.
1942		Pierre Laval, the premier of Vichy France, in a radio broadcast, establishes a policy of "true reconciliation with Germany."
1945		Soviet troops begin their attack on Berlin.
1951		General MacArthur addresses a joint session of Congress after being relieved by President Truman.
1953		Operation Little Switch begins in Korea, the exchange of sick and wounded prisoners of war.
1962		The New Orleans Citizens Committee gives free one-way ride to blacks to move North.
1967		U.S. planes bomb Haiphong for first time during the Vietnam War.
1999		Two students enter Columbine High School in Littleton, Colorado and open fire with multiple firearms, killing 13 students and teachers, wounding 25 and eventually shooting themselves.
Born on April 20
121		Marcus Aurelius, 16th Roman emperor, philosopher.
1745		Philippe Pinel, founder of psychiatry.
1807		Aloysius Bertrand ("Gaspard de la Nuit"), French poet.
1808		Louis-Napoleon (Napoleon III), emperor of France.
1850		Daniel Chester French, sculptor.
1889		Adolf Hitler, Facist dictator of Nazi Germany (1933-1945).
1893		Harold Lloyd, film comedian.
1893		Joan Miró, Spanish painter.
1927		Alex Muller, Nobel Prize-winning physicist