April 18 » The Greco-Turkish War is declared between Greece and the Ottoman Empire.
April 30 » J. J. Thomson of the Cavendish Laboratory announces his discovery of the electron as a subatomic particle, over 1,800 times smaller than a proton (in the atomic nucleus), at a lecture at the Royal Institution in London.
July 2 » British-Italian engineer Guglielmo Marconi obtains a patent for radio in London.
August 10 » German chemist Felix Hoffmann discovers an improved way of synthesizing acetylsalicylic acid (aspirin).
August 21 » Oldsmobile, an American automobile manufacturer and marque, is founded.
September 10 » Lattimer massacre: A sheriff's posse kills 19 unarmed striking immigrant miners in Lattimer, Pennsylvania, United States.
Day of marriage April 15, 1920
The temperature on April 15, 1920 was between 8.6 °C and 18.0 °C and averaged 12.6 °C. There was 0.7 mm of rain. There was 4.2 hours of sunshine (30%). The average windspeed was 5 Bft (very strong wind) and was prevailing from the south. Source: KNMI
In The Netherlands , there was from September 9, 1918 to September 18, 1922 the cabinet Ruys de Beerenbrouck I, with Jonkheer mr. Ch.J.M. Ruys de Beerenbrouck (RKSP) as prime minister.
January 17 » Alcohol Prohibition begins in the United States as the Volstead Act goes into effect.
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.
July 20 » The Greek Army takes control of Silivri after Greece is awarded the city by the Paris Peace Conference; by 1923 Greece effectively lost control to the Turks.
July 29 » Construction of the Link River Dam begins as part of the Klamath Reclamation Project.
August 13 » Polish–Soviet War: The Battle of Warsaw begins and will last till August 25. The Red Army is defeated.
October 10 » The Carinthian plebiscite determines that the larger part of the Duchy of Carinthia should remain part of Austria.
Day of death March 13, 1989
The temperature on March 13, 1989 was between 6.0 °C and 11.0 °C and averaged 8.5 °C. There was 0.5 mm of rain during 2.6 hours. There was 0.6 hours of sunshine (5%). The partly or heavily clouded was. The average windspeed was 4 Bft (moderate breeze) and was prevailing from the west-southwest. Source: KNMI
In The Netherlands , there was from Tuesday, November 4, 1986 to Tuesday, November 7, 1989 the cabinet Lubbers II, with Drs. R.F.M. Lubbers (CDA) as prime minister.
In The Netherlands , there was from Tuesday, November 7, 1989 to Monday, August 22, 1994 the cabinet Lubbers III, with Drs. R.F.M. Lubbers (CDA) as prime minister.
February 14 » Iranian leader Ruhollah Khomeini issues a fatwa encouraging Muslims to kill Salman Rushdie, author of The Satanic Verses.
June 21 » The U.S. Supreme Court rules in Texas v. Johnson, 491 U.S. 397, that American flag-burning is a form of political protest protected by the First Amendment.
August 19 » Several hundred East Germans cross the frontier between Hungary and Austria during the Pan-European Picnic, part of the events that began the process of the Fall of the Berlin Wall.
November 16 » El Salvadoran army troops kills six Jesuit priests and two others at Jose Simeon Canas University.
December 2 » The Peace Agreement of Hat Yai is signed and ratified by the Malayan Communist Party (MCP) and the governments of Malaysia and Thailand, ending the over two-decade-long communist insurgency in Malaysia.
December 25 » Romanian Revolution: Deposed President of Romania Nicolae Ceaușescu and his wife, Elena, are condemned to death and executed after a summary trial.
When copying data from this family tree, please include a reference to the origin: Hans Weening, "Family tree Weening", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-weening/I1759.php : accessed September 30, 2026), "Vogeltje Koopmans (1897-1989)".
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