The document summarizes key events around the US entry into World War 1 and its conclusion. It describes how Germany's unrestricted submarine warfare led the US to declare war in 1917, after German sabotage plans aimed at Mexico were intercepted. With millions of American troops joining the Allied forces, Germany was pushed back and surrendered in 1918. The Treaty of Versailles held Germany responsible for starting the war and imposed penalties, sowing resentment that impacted postwar Europe.