What you'll learn
Period 5 (1844–1877) spans westward expansion, the sectional crisis, the Civil War, and Reconstruction — ~10–17% of the APUSH exam and a frequent essay focus.
Manifest Destiny & expansion
- Manifest Destiny justified westward expansion; the Mexican-American War (1846–48) added vast territory (Mexican Cession).
- New land reignited the question: would it be free or slave?
The sectional crisis
- Compromise of 1850 (incl. a stronger Fugitive Slave Act), Kansas-Nebraska Act (1854) → popular sovereignty → "Bleeding Kansas."
- Dred Scott (1857) ruled Congress couldn't ban slavery in territories.
- Lincoln's 1860 election triggered Southern secession.
The Civil War (1861–65)
- Union advantages: industry, population, railroads, navy.
- Emancipation Proclamation (1863) reframed the war around slavery and allowed Black enlistment.
- Turning points: Gettysburg & Vicksburg (1863). The 13th Amendment (1865) abolished slavery.
Reconstruction (1865–77)
- 13th, 14th (citizenship/equal protection), 15th (Black male suffrage) Amendments.
- Conflict between Presidential and Radical (Congressional) Reconstruction.
- Gains (Black political participation, Freedmen's Bureau) undermined by Black Codes, the KKK, and ultimately the Compromise of 1877, which ended Reconstruction.
Key themes (for DBQ/LEQ)
- Slavery as the central cause of sectional conflict and war.
- Continuity and change: legal freedom vs. persistent inequality.
- Expansion of federal power and citizenship.
Exam tips
- Argue causation for the war with specific evidence (acts, court cases, elections).
- Evaluate Reconstruction's successes AND failures.
Common mistakes
- Reducing the war's cause to 'states' rights' without connecting it to slavery.
- Treating the Reconstruction Amendments as immediately effective in practice.