1920 events in history

Jan 1 The Belorussian Communist Organisation is founded as a separate party
Jan 2 The second Palmer Raid takes place with another 6,000 suspected communists and anarchists arrested and held without trial. These raids take place in several U.S. cities
Jan 7 The New York State Assembly refuses to seat five duly elected Socialist assemblymen
Jan 8 The steel strike of 1919 ends in a complete failure for the Amalgamated Association of Iron, Steel and Tin Workers labor union
Jan 10 The Treaty of Versailles takes effect, officially ending World War I
Jan 16 The League of Nations holds its first council meeting in Paris, France
Jan 16 Zeta Phi Beta Sorority Incorporated was founded on the campus of Howard University
Jan 19 The United States Senate votes against joining the League of Nations
Jan 20 The American Civil Liberties Union is founded
Jan 23 The Netherlands refuses to surrender the exiled Kaiser Wilhelm II of Germany to the Allies
Jan 26 Former Ford Motor Company executive Henry Leland launches the Lincoln Motor Company which he later sold to his former employer
Feb 1 The Royal Canadian Mounted Police begins operations
Feb 2 The Tartu Peace Treaty is signed between Estonia and Russia
Feb 2 France occupies Memel
Feb 9 Under the terms of the Svalbard Treaty, international diplomacy recognizes Norwegian sovereignty over Arctic archipelago Svalbard, and designates it as demilitarized
Feb 10 Jozef Haller de Hallenburg performs symbolic wedding of Poland to the sea, celebrating restitution of Polish access to open sea
Feb 13 The Negro National League is formed
Feb 14 The League of Women Voters is founded in Chicago
Feb 24 The Nazi Party is founded
Feb 26 The first German Expressionist film and early horror movie, Robert Wiene's The Cabinet of Dr. Caligari, receives its première in Berlin
Feb 29 Czechoslovak National assembly adopted the Constitution
Mar 8 The Arab Kingdom of Syria, the first modern Arab state to come into existence, is established
Mar 13 The Kapp Putsch briefly ousts the Weimar Republic government from Berlin
Mar 19 The United States Senate rejects the Treaty of Versailles for the second time (the first time was on November 19, 1919)
Mar 22 Azeri and Turkish army soldiers with participation of Kurdish gangs attacked the Armenian inhabitants of Shushi (Nagorno Karabakh)
Mar 28 Palm Sunday tornado outbreak of 1920 affects the Great Lakes region and Deep South states
Apr 15 Two security guards are murdered during a robbery in South Braintree, Massachusetts. Anarchists Sacco and Vanzetti would be convicted of and executed for the crime, amid much controversy
Apr 23 The Grand National Assembly of Turkey (TBMM) is founded in Ankara, Turkey. It denounces the government of Sultan Mehmed VI and announces the preparation of a temporary constitution
Apr 25 At the San Remo conference, the principal Allied Powers of World War I adopt a resolution to determine the allocation of Class "A" League of Nations mandates for administration of the former Ottoman-ruled lands of the Middle East
Apr 28 Azerbaijan is added to the Soviet Union
Apr 30 Peru becomes a signatory to the Buenos Aires copyright treaty
May 2 The first game of the Negro National League baseball is played in Indianapolis
May 3 A Bolshevik coup fails in the Democratic Republic of Georgia
May 5 Authorities arrest Nicola Sacco and Bartolomeo Vanzetti for alleged robbery and murder
May 7 Kiev Offensive: Polish troops led by Józef Piłsudski and Edward Rydz-Śmigły and assisted by a symbolic Ukrainian force capture Kiev only to be driven out by the Red Army counter-offensive a month later
May 7 The Art Gallery of Ontario, in Toronto, opens the first exhibition by the Group of Seven
May 7 Treaty of Moscow: Soviet Russia recognizes the independence of the Democratic Republic of Georgia only to invade the country six months later
May 9 Polish-Soviet War: The Polish army under General Edward Rydz-Śmigły celebrates its capture of Kiev with a victory parade on Khreschatyk
May 16 In Rome, Pope Benedict XV canonizes Joan of Arc
May 20 Montreal, Quebec radio station XWA broadcasts the first regularly scheduled radio programming in North America
Jun 4 Hungary loses 71% of its territory and 63% of its population when the Treaty of Trianon is signed in Paris
Jun 11 During the U.S. Republican National Convention in Chicago, U.S. Republican Party leaders gathered in a room at the Blackstone Hotel to come to a consensus on their candidate for the U.S. presidential election, leading the Associated Press to first coin the political phrase "smoke-filled room"
Jun 15 A new border treaty between Germany and Denmark gives northern Schleswig to Denmark
Jun 15 Duluth lynchings in Minnesota
Jul 11 In the East Prussian plebiscite the local populace decides to remain with Weimar Germany
Jul 12 The Soviet–Lithuanian Peace Treaty is signed. Soviet Russia recognizes independent Lithuania
Jul 15 The Polish Parliament establishes Silesian Voivodeship before the Polish-German plebiscite
Jul 25 France captures Damascus
Jul 29 Construction of the Link River Dam begins as part of the Klamath Reclamation Project
Aug 10 World War I: Ottoman sultan Mehmed VI's representatives sign the Treaty of Sèvres that divides up the Ottoman Empire between the Allies