Lesson 1 1. The United States was more sympathetic to the Allies because of the long history between the U.S. and Great Britain. The common culture of these two nations and the economic relationships between them made the U.S. more sympathetic to the Allies. 2. British propaganda, unrestricted German submarine warfare, and the sinking of the Lusitania had helped sway American public opinion toward the Allies. Germany sent the Zimmermann telegram, which tried to bring Mexico into the war by promising the return of “lost territory in Texas, New Mexico, and Arizona.” Finally, Germany’s resumption of unrestricted submarine warfare convinced the United States to declare war.

Lesson 2 3. Some women took jobs traditionally held by men or worked in factories. Others enlisted in the military to provide clerical support. Many African Americans migrated north to support the war effort by working in factories. Everyone worked to ration food and fuel to support the needs of the troops overseas. 4. The government passed the Espionage and Sedition Acts, making it illegal to print information opposed to the war or speak against the war publicly, which curtailed First Amendment freedoms. The Supreme Court nevertheless upheld these laws under the “clear and present danger” test.

Lesson 3 5. Many new military technologies debuted during World War I, such as artillery, poison gas, armored tanks, and military aircraft. The weapons changed the nature of modern warfare. 6. The arrival of U.S. troops made many Germans believe that they would lose the war, damaging their morale. U.S. forces helped reinforce Allied forces damaged by casualties, and the U.S. troops led a successful wide-scale attack in the Battle of the Argonne to push back the Germans.

Lesson 4 7. The end of World War I brought inflation, layoffs, and lowered wages. Unionized workers wanted higher wages and shorter working hours, but businesses resisted. Returning veterans could not find work and blamed African Americans. These circumstances led to labor and racial tensions. 8. Americans had long associated communism with unionization efforts, and the Russian Revolution seemed to justify fears. Violence at strikes and bombings further encouraged the Red Scare, as did the actions of Attorney General Palmer.

21st Century Skills 10. The Selective Service Act required men to sign up for the draft, which ensured a large pool of troops. A lottery then determined which men came before their local draft boards, and these boards decided whom to conscript. 11. The new weapons were deadly on a previously unknown scale. New tactics had to be developed to protect troops from these weapons. 12. Economic problems led to labor unrest and strikes in 1919 even as numerous bombs were mailed or detonated in the United States. As a result, people began to fear a Communist takeover. Palmer instituted raids that further stirred up fears, even though they proved to be without much factual basis. States began outlawing speech against the government, and the New York legislature even ejected Socialist politicians.

Document-Based Questions 14. The Foreign Relations Committee would not pass the treaty without certain amendments. Henry Cabot Lodge is shown by the author as helping the treaty come out of the “operating room” because the treaty was “slaughtered” during its review. 15. President Wilson did not want to compromise. He believed that the League of Nations would stand together if any member was threatened, and the approval of Congress to act might delay or undermine the effectiveness of the League.

Discussion How did the European alliances contribute to the start of World War I? After Archduke Franz Ferdinand’s assassination, Austria attacked Serbia. Because of a network of pledged defensive alliances the attack on Serbia began a domino effect of alliance responses that resulted in war across Europe.

Discussion How did the Russian Revolution affect the two warring sides? Russia left the war, allowing the Germans to focus on the Western front.

Discussion Describe in your own words why this war was a world war. World War I involved, in one way or another, many of the nations on Earth and was fought on several continents.

Discussion What were trenches? Trenches were long ditches and tunnels that served to mark the front lines of the warring powers.