AP U.S. History · Lesson 2

World War I and the 1920s

Know Know it

When war began in Europe in 1914, Wilson declared neutrality, but trade and loans tied the United States more and more to Britain and France. German submarines sank ships carrying Americans, among them the British liner Lusitania in 1915. In early 1917 Germany resumed unrestricted submarine warfare, and the Zimmermann Telegram revealed a German offer of an alliance to Mexico. Congress declared war in April 1917.

The war expanded federal power. The War Industries Board directed production, and the Committee on Public Information spread pro-war messages. The Espionage Act (1917) and the Sedition Act (1918) punished interference with the war effort and, under the Sedition Act, disloyal criticism; in Schenck v. United States (1919) the Supreme Court upheld a conviction for anti-draft leaflets under a clear and present danger test. War jobs drew hundreds of thousands of Black Southerners north in the Great Migration, and women's war work strengthened the case for the Nineteenth Amendment. The Eighteenth Amendment brought national Prohibition, in force from 1920.

Wilson's Fourteen Points (1918) called for open diplomacy, freedom of the seas, lower trade barriers, self-determination for nations and a League of Nations. The Senate rejected the Treaty of Versailles. Critics led by Henry Cabot Lodge feared that the League's promise to protect members could pull the nation into war without a vote of Congress.

After the war came the First Red Scare (1919 to 1920): strikes and bombings set off the Palmer Raids, in which federal agents arrested thousands of suspected radicals, many of them immigrants, and deported hundreds. The Immigration Act of 1924 set national-origins quotas that sharply cut immigration from southern and eastern Europe and barred nearly all immigration from Asia.

The 1920s mixed the new and the old. Republican presidents Harding, Coolidge and Hoover favored business, lower taxes and high tariffs. Radio, movies, cars and buying on credit spread a national consumer culture, and the Harlem Renaissance brought Black writers and musicians such as Langston Hughes and Zora Neale Hurston wide audiences. At the same time, a revived Ku Klux Klan attacked immigrants, Catholics, Jews and African Americans, Prohibition fed bootlegging and organized crime, and the 1925 Scopes trial set modernists against religious fundamentalists over teaching evolution.

Trap Staying out of the League is not staying out of the world

Rejecting the League of Nations did not make the United States isolated in the 1920s. It hosted the Washington Naval Conference (1921 to 1922) to limit warships, helped arrange loans to ease Germany's reparations, signed the Kellogg-Briand Pact (1928), and its trade and investment abroad grew. A question about the 1920s that says the nation 'withdrew from world affairs' is overstating.

Worked example Easy

Which event in early 1917 pushed the United States toward entering World War I?

  1. The sinking of the Lusitania
  2. Germany’s return to unrestricted submarine warfareAnswer
  3. The Senate’s vote against joining the League of Nations
  4. The Palmer Raids against suspected radicals

How to solve it

  1. Check the date in the stem: early 1917.
  2. Only the renewed submarine campaign happened then; the other choices are from 1915 or after the war.

Why each choice is right or wrong

  • A. Incorrect. The Lusitania was sunk in 1915, two years earlier, and Wilson kept the nation neutral after it.
  • B. Correct. In early 1917 Germany resumed sinking ships without warning, including American ones, and Congress declared war that April.
  • C. Incorrect. The Senate rejected the treaty with the League in 1919 and 1920, after the war was over.
  • D. Incorrect. The Palmer Raids came in 1919 and 1920, during the Red Scare after the war.

Explain Explain it

Task verbs: explain, compare

When you explain a change on the home front, name the specific law, agency or movement and then say who it affected and how. When you compare Wilson's war aims with what happened after the war, hold his stated goals against the Senate's and the public's response.

Worked example Medium

From Woodrow Wilson, address to Congress asking for a declaration of war, April 2, 1917 (public domain)

The world must be made safe for democracy. Its peace must be planted upon the tested foundations of political liberty. We have no selfish ends to serve. We desire no conquest, no dominion.

The goals in this excerpt are most consistent with which proposal Wilson made the following year?

  1. Annexing Germany’s colonies in Africa as U.S. territory
  2. A league of nations to guarantee the independence of large and small statesAnswer
  3. Heavy reparations and harsh terms meant to keep Germany weak for a generation
  4. A ban on all immigration from Germany and Austria-Hungary

How to solve it

  1. The excerpt rejects conquest and ties peace to political liberty.
  2. In 1918 Wilson's Fourteen Points turned those aims into a program that ended with a league of nations.

Why each choice is right or wrong

  • A. Incorrect. Annexing colonies would be conquest and dominion, which the excerpt says the nation does not desire.
  • B. Correct. Wilson's Fourteen Points of January 1918 ended with a call for an association of nations to protect every state's independence, matching the excerpt's selfless, democratic aims.
  • C. Incorrect. Crushing reparations were pushed mainly by Britain and France; Wilson's program in 1918 called for a fair peace.
  • D. Incorrect. Wilson made no such proposal, and an immigration ban has nothing to do with the excerpt's goals of liberty and peace.

Explain Your turn

Explain two ways World War I changed life on the American home front: one about work or the economy, and one about civil liberties.

Write it, then compare. Nothing you type here is saved or graded.

Compare with a model answer

A full answer does this

  • Gives an accurate wartime change in work or the economy
  • Gives an accurate wartime limit on civil liberties

Model answer

The war changed work: factories hungry for labor drew hundreds of thousands of Black Southerners to northern cities in the Great Migration, and the War Industries Board told industries what to produce. It also limited civil liberties: the Espionage Act of 1917 and the Sedition Act of 1918 punished people who criticized the war or the draft, and the Supreme Court upheld such a conviction in Schenck v. United States.

Apply Apply it

Practice these topics. AP Practice questions on exactly what this lesson covers, with an explanation for every answer.