Period 7: Progressive Era through WWII · 1890–1945
Everything you need to master Unit 7 — American imperialism and the Spanish-American War, the Progressive Era's reforms, World War I and the Treaty of Versailles, the Roaring Twenties, the Great Depression and FDR's New Deal, and World War II.
8–10% of the AP exam
7 study resources
College Board aligned
100% free
Choose how you want to study
Seven free resources for Unit 7 — pick the one that fits how you learn.
Unit 7 covers Period 7: Progressive Era through WWII, 1890–1945 — when America became a global superpower. The U.S. acquired its first overseas empire after the Spanish-American War, then turned inward to address industrial-era abuses through the Progressive Movement. World War I, the Roaring Twenties, the Great Depression, FDR's New Deal, and World War II each transformed American government, economy, and society at unprecedented scale.
The College Board wants you to understand American imperialism (Hawaii, Spanish-American War, Open Door Policy), Progressive reforms (Roosevelt's Square Deal, the 16th–19th Amendments, muckrakers), World War I and the rejection of the Treaty of Versailles, the 1920s cultural clashes (Prohibition, Scopes Trial, Harlem Renaissance, immigration restriction), the Great Depression and New Deal (FDR's 3 R's, Social Security), and WWII (Pearl Harbor, the home front, Japanese internment, the atomic bomb).
Unit 7 makes up roughly 10–17% of the AP US History exam — heavily tested because it transformed federal power, foreign policy, and American society more than any period since the Civil War.
Key terms preview
A taste of what you'll find in The Essentials and Flashcards.
Spanish-American War
1898 war triggered by the USS Maine and yellow journalism; U.S. won Puerto Rico, Guam, the Philippines, and effective control of Cuba — became a global power.
Progressivism
Early-1900s reform movement attacking industrial abuses, political corruption, and social inequities; demanded government action and produced the 16th–19th Amendments.
Theodore Roosevelt
26th president (1901–09); progressive Republican who busted trusts, regulated business, and supported conservation — promised a 'Square Deal' for all.
Treaty of Versailles
1919 treaty ending WWI; Senate rejected it because of opposition to the League of Nations led by Henry Cabot Lodge.
New Deal
FDR's 1933+ program responding to the Great Depression; the '3 R's' — Relief, Recovery, Reform — massively expanded federal government.
Pearl Harbor
December 7, 1941 Japanese surprise attack on the U.S. naval base in Hawaii; brought the U.S. into WWII.
In 55 years, America went from an isolated republic to the dominant world power. The Spanish-American War made the U.S. an empire; WWI made it the world's creditor; WWII made it the strongest military and economic power on Earth, with atomic weapons and global responsibilities.
2. Federal government expanded massively — through reform, depression, and war
Each phase enlarged federal power: Progressive Era regulation and constitutional amendments (16th–19th); WWI mobilization and the Espionage Act; the New Deal's alphabet agencies and Social Security; WWII's total industrial mobilization. The activist federal government of modern America was built in this period.
3. American society underwent radical demographic and cultural change
The Great Migration moved millions of Black Americans north; women gained the vote (1920) and joined the WWII workforce; immigration was restricted by the National Origins Act; the Harlem Renaissance redefined Black culture; and Japanese American internment showed the limits of civil liberties during war.