The document provides background information on the USA and its entry into World War 1 in 1917. It discusses the USA's policy of isolationism prior to the war and its political system and parties. It then covers reasons why the US joined the war in 1917, including Germany resuming unrestricted submarine warfare which threatened US trade. President Wilson played a role in the Treaty of Versailles but the US Senate ultimately rejected joining the League of Nations. The war resulted in increased US trade and industry while isolationism increased following the war.