Unit 4: Period 4 (1800–1848)
AP US History: 54 practice questions with detailed explanations.
Unit Study Guide
Executive Summary
Period 4 covers the growth of democracy, the market revolution, westward expansion, reform, and the sectional tensions that foreshadowed civil war.
Jeffersonian democracy
Jefferson's 1800 election marked the first peaceful party transfer. The Louisiana Purchase (1803) doubled the nation's size; Lewis and Clark explored it. The Supreme Court under Marshall asserted judicial review (Marbury v. Madison, 1803) and federal supremacy (McCulloch v. Maryland, 1819).
The War of 1812 and the Era of Good Feelings
The war with Britain ended in a draw but boosted nationalism. The Monroe Doctrine (1823) warned Europe out of the hemisphere. The Missouri Compromise (1820) admitted Missouri slave and Maine free, drawing the 36°30′ line.
Jacksonian democracy
Andrew Jackson expanded white male suffrage, spoils politics, and presidential power. He vetoed the Second Bank and forced Indian removal — the Trail of Tears (1830s). The Nullification Crisis (1832–33) saw South Carolina challenge federal tariffs.
Market revolution
Canals (Erie), railroads, steamboats, and factories tied regions together. The cotton gin made cotton king, entrenching slavery. Lowell mills employed young women; immigration surged from Ireland and Germany.
Reform and sectionalism
The Second Great Awakening fueled abolition, temperance, education, and women's rights. Seneca Falls (1848) demanded women's suffrage. Transcendentalism (Emerson, Thoreau) championed individualism. Sectional conflict over slavery's expansion deepened with the Mexican War on the horizon.
Exam traps
Jackson's democracy was for WHITE men — it excluded women, Natives, and African Americans. The Monroe Doctrine was backed by British naval power, not American might. The market revolution linked regions but sharpened slavery's expansion. Indian removal was policy, not accident.