<human>:  What were the major events of the First World War?
<bot>: The major events of the First World War included the start of the conflict on June 28, 1914, with the assassination of Archduke Franz Ferdinand of Austria, the entry of the United States into the war in April 1917, the Treaty of Versailles in June 1919, the collapse of the German and Austro-Hungarian Empires in November 1918, and the armistice in November 1918.