World Wars By Walkerr Jun 28, 1914 Archduke Franz Ferdinand Assasinated Period: Jul 28, 1914 to Nov 11, 1918 World War 1 Jul 30, 1914 Russia Mobilizes Aug 4, 1914 Germany Invades Belgium Apr 22, 1915 Germans Use Chlorine Gas on a large scale Sep 18, 1915 Lusitania Sinks Sep 15, 1916 First Tanks Deployed by the British Sep 18, 1916 Germany Limits Submarines To prevent America from joining the war Feb 1, 1917 Germany Unrestricted Submarines This brings America into the war and lead to Germany's defeat Feb 25, 1917 Zimmerman Telegram Apr 2, 1917 President Wilson outlines his case for war to Congress. Apr 6, 1917 U.S. Enters War Period: Jun 28, 1919 to Jan 21, 1920 The Treaty of Versailles Period: Jan 1, 1920 to Dec 31, 1929 The Roaring Twenties Period: Sep 29, 1929 to 1939 Great Depression Period: Sep 1, 1939 to Sep 2, 1945 World War 2 Apr 30, 1945 Adolf Hitler Died