IMPORTANT DATES RELATING TO THE HOLOCAUST 1919 May 7: Signing of the Versailles Peace Treaty ends World War I 1932 Hitler receives 37% of the vote during national elections; the NSDAP becomes the largest party in Germany. 1933 January 27: Hitler becomes leader of Germany 1933 March: 10,000 active labor union members are arrested in Germany 1933 March 23: Hitler acquires absolute power in Germany 1933 Catholic Bishops declare loyalty to Hitler 1933 April 1: Joseph Goebbels declares the official boycott of Jewish shopkeepers, doctors and lawyers 1935 Nuremberg laws are passed 1937 Gestapo sterilizes 385 black children 1938 November 9-11: Crystal Night (Kristallnacht) takes place 1938 November 12: first mass arrests of Jews 1939 January 30: Hitler announces “the destruction of the Jewish race” 1939 September 1: German troops attack Poland 1941 February: Wannsee Conferenz