Khan Academy
Khan Academy: Ap Us History: 1890 1945: The United States in World War I
Discusses what triggered World War I, why the United States joined the war, and the impact the war had on life in the United States. Includes questions for students at end.
The History Cat
The History Cat: America Enters the Ring
Describes the events leading up to America's entry into World War I and the changes that took place in America soon after. These included legislation such as the Selective Service Act and the Espionage and Sedition Acts, protests by...
World War 1
Worldwar1.com: Trenches on the Web: Armory: U Boats: Assassins of the Seas
This site contains pictures, charts and general information on Germany's use of submarine warfare. It focuses on the second phase of submarine usage, i.e., to disrupt trade lines and enforce embargos.