Part two of a 15-part series of documentaries produced by the American Broadcasting Company on the 20th century and the rise of the United States as a superpower.

From the assassination of Archduke Ferdinand in Sarejevo in June of 1914 to Armistice Day in November of 1918, the world was embroiled in the First World War. World War I not only shaped much of the events of the twentieth century but also was truly unique since it was the first "mechanized" war. This episode documents the development of the war and American foreign policy regarding both war and peace.