what month did the first world war start
World War I World War I (often abbreviated as WWI or WW1), also known as the First World War or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as the "war to end all wars",[7] more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history.[8][9] Over nine million combatants and seven million civilians died as a result of the war (including the victims of a number of genocides), a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. It was one of the deadliest conflicts in history and precipitated major political change, including the Revolutions of 1917–1923 in many of the nations involved. Unresolved rivalries at the end of the conflict contributed to the start of the Second World War twenty-one years later.[10]
World War I In January 1917, Germany resumed unrestricted submarine warfare, realizing it would mean American entry. The German Foreign Minister, in the Zimmermann Telegram, invited Mexico to join the war as Germany's ally against the United States. In return, the Germans would finance Mexico's war and help it recover the territories of Texas, New Mexico, and Arizona.[150] The United Kingdom intercepted the message and presented it to the U.S. embassy in the U.K. From there it made its way to President Wilson who released the Zimmermann note to the public, and Americans saw it as casus belli. Wilson called on antiwar elements to end all wars, by winning this one and eliminating militarism from the globe. He argued that the war was so important that the U.S. had to have a voice in the peace conference.[151] After the sinking of seven U.S. merchant ships by submarines and the publication of the Zimmermann telegram, Wilson called for war on Germany,[152] which the U.S. Congress declared on 6 April 1917.
American entry into World War I On December 7, 1917, the U.S. declared war on Austria-Hungary.[5][6]
World War II The start of the war in Europe is generally held to be 1 September 1939,[9][10] beginning with the German invasion of Poland; Britain and France declared war on Germany two days later. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937,[11][12] or even the Japanese invasion of Manchuria on 19 September 1931.[13][14]