| A | B |
| World War I | 1914-1918. Allies (Britain; France; Russia; & US) defeated Central Powers (Germany; Austria-Hungary; Ottoman Empire). |
| Unrestricted Submarine Warfare | Germany's Policy of sinking ships (military; commercial; or passenger) with their U-boats; enemy or neutral. |
| Zimmerman Telegram | Sent by Germans to encourage a Mexican attack against the United States. Intercepted & decoded by Britain. |
| Great Migration | Movement of over 300;000 African American from the rural south into Northern cities between 1914 and 1920 as they looked for jobs. |
| Espionage Act | 1917 law that provided penalties for spying; sabotage; and obstructing the war effort also banned the use of the United States Mail to send anti-war materials |
| Socialism | A system in which society; usually in the form of the government; owns and controls the means of production. |
| Eugene V. Debs | Prominent Socialist; four-time candidate for the presidency; and union leader. Convicted of violating Espionage Act and sentenced to 10 years in prison |
| Fourteen Points | A series of proposals in which U.S. president Woodrow Wilson outlined a plan for achieving a lasting peace after World War I. |
| League of Nations | An organization of nations formed after World War I to promote cooperation and peace. U.S. never joined. |
| Woodrow Wilson | 28th President of the United States (1913-1921) and the leading figure at the Paris Peace Conference of 1919. He was unable to persuade the U.S. Congress to ratify the Treaty of Versailles or join the League of Nations. |
| Treaty of Versailles | Treaty that ended WWI. It blamed Germany for WWI and handed down harsh punishments. |
| Declaration of Neutrality | Issued by Wilson after the outbreak of WWI in 1914; U.S. would have normal relations with both sides of the conflict. |
| Lusitania | A British passenger ship that was sunk by a German U-Boat on May 7; 1915. 128 Americans died. The sinking greatly turned American opinion against the Germans; helping the move towards entering the war. |