Period 7: 1890–1945

What this unit covers

The topics below follow the published US History course framework for Unit 7. This unit is worth 10–17% of the exam, so budget your time against that rather than against how long the unit takes to teach.

Lessons in this unit

• Progressivism & the Emergence of Empire14 min · 3 objectivesExplain the goals and achievements of the Progressive movement · Analyze how the Spanish-American War made the United States a world power · Evaluate the debate over American imperialism
• World War I & the 1920s13 min · 3 objectivesExplain why the United States entered World War I and the war’s domestic effects · Analyze the tension between traditionalism and modernism in the 1920s · Describe the causes of the Great Depression
• The New Deal & World War II15 min · 3 objectivesExplain how the New Deal reshaped the role of the federal government · Analyze the causes and consequences of U.S. entry into World War II · Describe how the war transformed American society and its global position
• Empire and the Debate Over It, 1890–191715 min · 3 objectivesExplain the economic, strategic, and ideological arguments for expansion · Analyze anti-imperialist arguments and the Philippine-American War · Describe the Roosevelt Corollary and dollar diplomacy
• The Depression's Causes and the New Deal's Limits15 min · 3 objectivesExplain the structural causes of the Great Depression beyond the crash · Distinguish the First and Second New Deals and their aims · Analyze who the New Deal excluded and why
• The Home Front: Mobilization, Internment, and the Double V15 min · 3 objectivesExplain how wartime mobilization ended the Depression and reshaped the economy · Analyze Japanese American internment and Korematsu · Describe wartime civil rights activism and its postwar consequences

Every term in Unit 7

All 43 terms we publish for Period 7: 1890–1945, with definitions. Reading them through is the fastest way to find the ones you cannot define — then drill those in cram mode until you can produce them without the prompt.

Muckrakers

Investigative journalists such as Ida Tarbell, Upton Sinclair, and Jacob Riis. Significance: mass-circulation exposés of Standard Oil, meatpacking, and tenement conditions created the public pressure behind the Pure Food and Drug Act and the Meat Inspection Act (1906).

Spanish-American War (1898)

Brief war yielding Puerto Rico, Guam and the Philippines, making the US an overseas empire and igniting the anti-imperialist debate.

Open Door Policy

Hay's demand for equal trading access to China, protecting American commerce without territorial conquest.

Roosevelt Corollary

Claimed a US right to intervene in Latin America to forestall European intervention; the basis of repeated occupations.

Pure Food and Drug Act (1906)

Passed with the Meat Inspection Act after The Jungle; established federal authority over product safety.

Sixteenth and Seventeenth Amendments

Federal income tax and direct election of senators, both 1913 — two Populist demands enacted by Progressives.

Eighteenth and Nineteenth Amendments

Prohibition (1919) and women's suffrage (1920), the twin culminations of decades of reform organizing.

Federal Reserve Act (1913)

Created a central banking system with an elastic currency to prevent the panics that had recurred since the 1870s.

Triangle Shirtwaist fire (1911)

146 garment workers, mostly young immigrant women, died behind locked doors. Produced a wave of state factory-safety and labor law.

Great Migration

Roughly six million Black Southerners moved to Northern and Western cities from 1916, driven by Jim Crow and wartime jobs, reshaping American politics and culture.

Zimmermann Telegram

German proposal that Mexico attack the US in exchange for lost territory. Its publication pushed American opinion toward war in 1917.

Schenck v. United States (1919)

Upheld Espionage Act convictions under the "clear and present danger" test — speech protections narrowed in wartime.

Fourteen Points

Wilson's peace program of self-determination, freedom of the seas, open diplomacy and a League of Nations. Largely abandoned at Versailles.

Red Scare (1919–20)

Post-war panic over radicalism producing the Palmer Raids and mass deportations without due process.

Harlem Renaissance

Flowering of Black literature, art and music in 1920s Harlem — Hughes, Hurston, Ellington — asserting cultural self-definition.

Scopes Trial (1925)

Tennessee evolution trial that dramatized the clash between modernist science and fundamentalist religion.

National Origins Act (1924)

Quotas pegged to the 1890 census to favor northern Europeans and bar most Asians. Cut immigration sharply until 1965.

Causes of the Great Depression

Overproduction, unequal income distribution, margin speculation, weak banks, farm debt and a tariff war that shrank world trade — not the crash alone.

Hoover's response

Voluntarism, public works and the Reconstruction Finance Corporation — real intervention by prior standards, but too small and too late.

First New Deal

1933–34 relief and recovery: banking holiday, CCC, AAA, NRA, TVA, FDIC. Aimed at stopping the collapse.

Second New Deal

1935–38 structural reform: Social Security, Wagner Act, WPA. Shifted from recovery to permanent protections.

Wagner Act (1935)

Guaranteed collective bargaining and created the NLRB. Union membership tripled within a decade.

Social Security Act (1935)

Old-age pensions, unemployment insurance and aid to dependent children. Excluded agricultural and domestic workers, leaving out most Black and Latino workers.

Court-packing plan (1937)

FDR's proposal to add justices after the Court struck down New Deal laws. Failed and cost him political capital, though the Court softened anyway.

Lend-Lease (1941)

Allowed the US to supply Britain and later the USSR without payment — the "arsenal of democracy" before formal belligerence.

Executive Order 9066

Authorized the internment of about 120,000 Japanese Americans, two-thirds of them citizens. Upheld in Korematsu; redress and apology came in 1988.

Double V campaign

Black wartime slogan demanding victory over fascism abroad and racism at home — a bridge to the postwar civil rights movement.

Rosie the Riveter

Symbol of the women who entered industrial work during the war. Most were pushed out afterward, but expectations had changed.

Manhattan Project

Secret program that built the atomic bomb, used on Hiroshima and Nagasaki in August 1945, ending the war and opening the nuclear age.

Alfred Thayer Mahan

Naval theorist whose The Influence of Sea Power upon History argued great powers need battle fleets, and fleets need coaling stations and canals — the case for Hawaii, Pacific bases and Panama.

Anti-Imperialist League

Coalition including Twain, Carnegie, Addams and Gompers opposing annexation of the Philippines on constitutional, economic and — for some members — racist grounds.

Philippine-American War (1899–1902)

War against Aguinaldo's independence forces after annexation: over four thousand American and, by conservative estimate, more than two hundred thousand Filipino deaths.

Insular Cases

Held the Constitution did not fully apply to unincorporated territories, creating a category of people under American sovereignty without full constitutional rights.

Dollar diplomacy

Taft's policy of substituting American investment for military intervention to secure influence, particularly in Latin America — in practice troops still followed.

Smoot-Hawley Tariff (1930)

Raised duties to record levels; retaliation followed and world trade collapsed by roughly two-thirds, deepening the global Depression.

Bank runs and the money supply

Thousands of small undiversified banks failed in cascades with no deposit insurance, destroying savings and contracting the money supply — a structural cause of the Depression's depth.

Agricultural Adjustment Act

Paid farmers to cut acreage to raise prices, controversially destroying crops amid hunger and displacing tenants and sharecroppers who worked the retired land.

Tennessee Valley Authority

Federal corporation building dams for flood control, electrification and regional development across seven states — the New Deal's most ambitious experiment in public planning.

Schechter v. United States (1935)

Struck down the NRA for delegating legislative power and overreaching the commerce clause, forcing the pivot to the Second New Deal.

Social Security exclusions

Agricultural and domestic workers were left out, excluding roughly two-thirds of Black workers — a concession to Southern Democrats built into the safety net's foundation.

Redlining

HOLC and FHA practice of rating Black and mixed neighborhoods as hazardous for lending regardless of income, denying federally backed mortgages and shaping the racial wealth gap.

Korematsu v. United States (1944)

Upheld Japanese American exclusion as military necessity; Murphy's dissent called it the legalization of racism. Repudiated by the Court in 2018.

442nd Regimental Combat Team

Largely Japanese American unit, many recruited from the internment camps, which became one of the most decorated in the Army — the war's sharpest internal contradiction.

What examiners penalize here

• A frequent DBQ theme: World War II, not the New Deal, finally ended the Depression by generating full employment. Yet the New Deal’s legacy is the **expanded, activist federal government**. Distinguishing the two shows the causation graders look for.
• For any 1898 prompt, sort your evidence into **economic / strategic / ideological** and give one specific piece under each. Three labeled causes with concrete evidence beats a paragraph of narrative every time, and it makes the "multiple causation" point almost automatic.
• Internment questions want more than condemnation. Name the numbers (**120,000**, two-thirds **citizens**), the legal instrument (**EO 9066**), the case (**Korematsu**), the absence of comparable treatment for German and Italian Americans, and the 1988 reparations. Specifics are what convert a moral judgment into a scored historical argument.

Practice US History

Our practice bank is drawn from across the whole course rather than filtered to one unit, which is closer to how the exam asks anyway — it will not tell you which unit a question is testing.

Questions about this unit

All 9 units of AP United States History

1. Unit 1 · Period 1: 1491–1607
2. Unit 2 · Period 2: 1607–1754
3. Unit 3 · Period 3: 1754–1800
4. Unit 4 · Period 4: 1800–1848
5. Unit 5 · Period 5: 1844–1877
6. Unit 6 · Period 6: 1865–1898
7. Unit 7 · Period 7: 1890–1945
8. Unit 8 · Period 8: 1945–1980
9. Unit 9 · Period 9: 1980–Present