Remembering The Veterans Of WWI April 6th, 1917 The United States Entered WWI World War I, also known as the First World War, and (before 1939) the Great War, the War of the Nations, and the War to End All Wars, was a world conflict lasting from August 1914 to the final Armistice on November 11, 1918. The Allied Powers (led by Britain, France (and Russia until 1917), and, after 1917, the United States) defeated the Central Powers (led by the German Empire, Austria-Hungary and the Ottoman Empire). The war caused the collapse of four empires and a radical...