Ricketts, John Steinbeck and six others leave Monterey, California, United States, for the Gulf of California, on a marine invertebrate collecting expedition. March 12 – Moscow Peace Treaty: The Soviet Union and Finland sign a peace treaty in Moscow, ending the Winter War; Finns, along with the world at large, are shocked by the harsh terms. March 13 – Indian nationalist Udham Singh assassinates Sir Michael O'Dwyer (in revenge for the 1919 Jallianwala Bagh massacre) at Caxton Hall in London, for which he is hanged on 31 July at HM Prison Pentonville. March 18 – WWII: Axis powers: Adolf Hitler and Benito Mussolini meet at Brenner Pass in the Alps. After being informed by Hitler that the Germans are ready to attack in the west, Mussolini agrees to bring Italy into the war in due course. March 21 – Édouard Daladier resigns as Prime Minister of France; Paul Reynaud succeeds him. March 23 – Pakistan Movement: The Lahore Resolution, calling for greater autonomy for what will become Pakistan in British India, is drawn up by the All-India Muslim League during a three-day general session at Iqbal Park, Lahore. March 30 – WWII: Former Kuomintang member and Chinese foreign minister, Wang Jingwei, announces the creation of the Reorganized National Government of the Republic of China in Nanjing. March 31 – WWII: Commerce raiding leaves the Wadden Sea for what will become the longest warship cruise of the war (622 days without in-port replenishment or repair). April April 3 – WWII: Operation Weserübung: German ships set out for the invasion of Norway. April 4 – Neville Chamberlain, UK Prime Minister, in what proves to be a tragic misjudgment, declares in a major public speech that Hitler has "missed the bus". April 7 – Booker T. Washington becomes the first African American to be depicted on a United States postage stamp. April 8 – WWII: Operation Wilfred: The British fleet lays naval mines off the coast of neutral Norway. April 9 – WWII: Germany invades the neutral countries of Denmark and Norway in Operation Weserübung, opening the Norwegian Campaign. The British Royal Navy attempts to attack elements of the German fleet off Norway. Vidkun Quisling proclaims a new collaborationist regime in Norway. The German invasion of Denmark lasts for about six hours, before that country capitulates. April 10 – WWII: First Naval Battle of Narvik: The British Royal Navy attacks the German fleet