APUSH · Period 5
— c. 1844 to c. 1877 —

The fight over slavery — and what came after.

Westward expansion forces the question the founders ducked. The political system breaks. Half a million U.S. soldiers die. And the Reconstruction that should have remade the South is allowed, by 1877, to fail.

What you need to know

The Mexican Cession (1848) puts a continent of new territory on the table — and the question of whether slavery follows the flag becomes unavoidable. Compromise of 1850, Uncle Tom’s Cabin (1852), Kansas-Nebraska (1854), Dred Scott (1857), Lincoln-Douglas (1858), Harpers Ferry (1859), Lincoln’s election (1860), secession (1860–61), and a four-year war whose body count exceeded all other U.S. wars combined. The Emancipation Proclamation transformed the war’s purpose. The 13th, 14th, and 15th Amendments wrote a new constitutional order. Reconstruction (1865–1877) tried to enforce it — federal troops, Black political participation, the first public schools in the South — and was systematically rolled back by terror (Klan), Supreme Court retreat (Slaughter-House, Cruikshank), and finally the Compromise of 1877.

AMSCO Reading — 4th edition

Read Unit 5 alongside this period.

Pages 260–345 (86 pp.) cover topics 5.1–5.12 — all 12 CED topics for the 1844–1877 window.

The site’s topic accordions match AMSCO’s numbering (1.1, 1.2…). Read AMSCO’s overview for each topic, then expand the matching accordion below for the site’s study notes, key terms, and exam-focus tips.

Period topics (6)

The CED, topic by topic.

  • 5.1

    Manifest Destiny and the Sectional Crisis

    Continental expansion forces the slavery question to a breaking point.GEO · NAT · MIG

    What to study

    Manifest Destiny — the idea that the U.S. was divinely entitled to the continent — drove the annexation of Texas (1845), the Oregon settlement (1846), and the Mexican-American War (1846–1848). The Treaty of Guadalupe Hidalgo added the entire Southwest plus California. Each new territory raised the same question: free or slave? The Compromise of 1850, the Kansas-Nebraska Act (1854), “Bleeding Kansas,” the *Dred Scott* decision (1857), John Brown’s raid (1859), and Lincoln’s election (1860) — every compromise made the next crisis bigger. The Republican Party (founded 1854) emerged on a platform of free soil — no slavery in new territories.

    Key termsManifest Destiny · Texas annexation · Mexican-American War · Compromise of 1850 · Kansas-Nebraska Act · Bleeding Kansas · Dred Scott v. Sandford · John Brown · Republican Party
    Exam focusCausation prompts on the Civil War want a CHAIN — show how each compromise made the next crisis harder, not easier.
    Primary sourceJohn L. O’Sullivan, Manifest Destiny, United States Magazine and Democratic Review, 1845 — Digital History, University of Houston
    O’Sullivan coins “manifest destiny” to justify continental expansion — the ideological engine of westward migration and sectional crisis over new territories.
    Whose story is missing?

    “The white man made us many promises, more than I can remember, but he never kept but one; he promised to take our land, and he took it.” — Red Cloud (Makḥp̣iyáluta), Oglala Lakota, speech at Cooper Institute, New York, 1870 (documented in the New York Tribune, June 17, 1870)

    Manifest Destiny is taught as U.S. ideology justifying continental expansion, but Red Cloud — who had won the only major military victory by a Native nation against the U.S. Army in Red Cloud’s War (1866–68) — came to New York in 1870 not as a defeated chief but as a diplomat demanding accountability. His Cooper Institute speech, delivered to 4,000 people and reported in full by the Tribune, directly named what Manifest Destiny meant from the receiving end: a decade of federal promises made and broken in sequence. The “negotiation” frame AP uses for U.S.-Indigenous relations in this period was experienced as coercion. Read the source →

  • 5.2

    The Civil War

    Four years that resolved one founding contradiction and exposed the next.PCE · NAT · ARC

    What to study

    Lincoln’s election triggered Southern secession (Dec 1860–Feb 1861) and war by April 1861. The Union’s advantages — population (22M vs. 9M, of whom 3.5M were enslaved), 90% of manufacturing, 70% of railroads, control of the navy — eventually overcame Confederate generalship. Key turning points: Antietam (1862, enabling the Emancipation Proclamation); Gettysburg + Vicksburg (July 1863); Sherman’s March to the Sea (1864); Appomattox (April 1865). The war killed ~750,000 — more than every other U.S. war combined. The 13th Amendment (1865) ended slavery. Lincoln’s assassination handed Reconstruction to Andrew Johnson — disastrously.

    Key termsFort Sumter · Anaconda Plan · Antietam · Emancipation Proclamation · Gettysburg Address · 13th Amendment · Appomattox · Lincoln assassination
    Exam focusDon’t lose evidence points listing battles. Pick TWO turning points and explain WHY each shifted the war (military, diplomatic, or political).
    Primary sourceAbraham Lincoln, First Inaugural Address, 1861 — Yale Avalon Project
    Lincoln denies any plan to end slavery where it exists while refusing to accept secession — the last diplomatic attempt before Fort Sumter.
    Whose story is missing?

    “This regiment has proved itself. We can fight. Now we demand the rights of men.” — Corporal James Henry Gooding, 54th Massachusetts Infantry, letter to President Lincoln, 1863

    AP covers the Civil War through military campaigns and political leadership, but 180,000 Black men served in the Union Army and their participation both enabled Union victory and transformed the war’s meaning. Corporal Gooding’s letter to Lincoln—protesting that Black soldiers were paid less than white soldiers for the same service—illustrates that African Americans understood the war as a negotiation over citizenship, not just a battle over secession. They were right: the 14th and 15th Amendments came directly from the claims Black soldiers made through their service. Read the source →

  • 5.3

    Reconstruction

    America’s first attempt at multiracial democracy — and its violent reversal.ARC · SOC · PCE

    What to study

    Reconstruction (1865–1877) tried to rebuild the South and integrate four million newly freed people into citizenship. The 14th Amendment (1868) guaranteed equal protection; the 15th (1870) guaranteed Black male suffrage. African Americans served in Congress, state legislatures, and local office across the South. Black-led churches, schools, and political organizations flourished. White Southern resistance — Black Codes, the KKK (founded 1866), Colfax Massacre (1873), Mississippi Plan (1875) — rolled back gains through terror. The Compromise of 1877 ended federal occupation; Jim Crow laws and *Plessy v. Ferguson* (1896) would lock in segregation for the next sixty years.

    Key termsFreedmen’s Bureau · 14th and 15th Amendments · Black Codes · Sharecropping · Ku Klux Klan · Compromise of 1877 · Redemption · Plessy v. Ferguson (1896)
    Exam focusAP wants you to explain BOTH the achievements (constitutional amendments, Black political participation) AND the reversal (violence, Jim Crow). An essay that ignores either half loses points.
    Primary sourceFourteenth Amendment to the U.S. Constitution, 1868 — Yale Avalon Project
    Citizenship, equal protection, due process — Reconstruction’s most consequential change, later the basis for 20th-century civil rights law.
    Whose story is missing?

    “We are men; we have souls, and hearts, and minds, and consciences… We claim the right of suffrage. We are loyal citizens. We have fought for this Union, and we are willing to continue to fight for it. We are taxed — we ask for representation.” — Petition of Black Citizens of Nashville to the Union Convention of Tennessee, January 9, 1865

    Three weeks before the Thirteenth Amendment was ratified, 59 Black Tennesseans — freedpeople, free Black men, and Black Union veterans — submitted this petition to the convention drafting Tennessee’s new constitution. They argued that military service, tax payment, and basic humanity entitled them to full citizenship and the vote. The convention initially refused to consider it. Their demands would be partially addressed by the Fourteenth and Fifteenth Amendments, and then systematically reversed by Jim Crow law, racial terror, and the Compromise of 1877. Du Bois’s Black Reconstruction (1935) is brilliant — but it is a secondary source written seventy years after these events. This is Reconstruction written in 1865, by the people it was supposed to benefit, making their case in their own words. Read the source →

  • 5.4

    Mexican-American War & Continental Expansion

    Polk’s war added the Southwest — and forced the slavery question into every new state debate.GEO · WOR · MIG

    What to study

    James K. Polk campaigned (1844) on annexing Texas and Oregon and won. Texas annexation (1845) led to the Mexican-American War (1846–48) — territorially the U.S.’s most lucrative war: the Treaty of Guadalupe Hidalgo (1848) added the entire Southwest plus California (525,000 sq mi for $15 million). Critics — including Whig congressman Abraham Lincoln (Spot Resolutions, 1847) and Henry David Thoreau (“Civil Disobedience,” 1849) — called it a war of slaveholder aggression. The Wilmot Proviso (1846) — banning slavery in any territory taken from Mexico — failed in the Senate but defined the sectional fight ahead. The 1849 California Gold Rush drew 300,000 settlers and triggered statehood under the Compromise of 1850.

    Key termsJames K. Polk · Treaty of Guadalupe Hidalgo (1848) · Wilmot Proviso · Free Soil Party · Spot Resolutions · ‘Civil Disobedience’ · Forty-Niners · Compromise of 1850 · Fugitive Slave Act (1850)
    Exam focusCausation prompts on the Civil War want a CHAIN: Mexican Cession (1848) → Wilmot Proviso → Compromise of 1850 → Kansas-Nebraska (1854) → Bleeding Kansas → Lincoln’s election (1860) → secession. Each step makes the next bigger.
    Primary sourceTreaty of Guadalupe Hidalgo, 1848 — Yale Avalon Project
    The treaty ending the Mexican-American War ceded half of Mexico’s territory to the U.S. — instantly reopening the slavery expansion debate.
    Whose story is missing?

    “I have seen old men of sixty and seventy years crying like children because they are compelled to leave the lands where they were born, where their parents are buried.” — Pablo de la Guerra, Californio, California State Senator, speech to the California Senate, 1856

    The Treaty of Guadalupe Hidalgo promised to protect the land grants and citizenship rights of Mexicans who became U.S. subjects in 1848, but those guarantees were systematically dismantled by U.S. courts and Land Commission proceedings that imposed expensive, years-long legal burdens on Californio families. Pablo de la Guerra — born into one of California’s oldest ranching families, later a state senator — watched as legal fees, squatters backed by Anglo courts, and deliberate procedural obstruction stripped Californio ranchos away. His 1856 Senate speech stands as one of the only Californio voices in the official record naming what dispossession actually looked like. Read the source →

  • 5.5

    Antebellum Reform Movements

    The Second Great Awakening sparks a reform era that takes American ideals seriously and turns them against the country.SOC · ARC · PCE

    What to study

    The Second Great Awakening (1790s–1840s) produced a reform generation that asked: if we believe in human perfectibility and equality, why does our country tolerate slavery, alcoholism, illiteracy, and the second-class treatment of women? Abolitionism: William Lloyd Garrison’s The Liberator (1831), Frederick Douglass’s Narrative (1845), Harriet Beecher Stowe’s Uncle Tom’s Cabin (1852), the Underground Railroad. Women’s rights: the Seneca Falls Convention (1848) and its Declaration of Sentiments deliberately echoed the Declaration of Independence. Temperance: ~5 million members in temperance societies by 1840. Asylum reform: Dorothea Dix exposed prison and asylum conditions. Public education: Horace Mann’s free common schools. Utopian experiments: Brook Farm, Oneida, Shakers, New Harmony. Transcendentalism: Emerson and Thoreau’s argument for self-reliance.

    Key termsSecond Great Awakening · William Lloyd Garrison · Frederick Douglass · Seneca Falls Convention (1848) · Declaration of Sentiments · Dorothea Dix · Horace Mann · Brook Farm · Transcendentalism · Underground Railroad
    Exam focusStrong DBQs on antebellum reform connect the religious energy (Awakening) to specific secular movements. Show CAUSATION, not coincidence — and don’t lose the women’s rights origins in abolitionism.
    Primary sourceWilliam Lloyd Garrison, The Liberator, Vol. I, No. 1, 1831 — Digital History, University of Houston
    Garrison’s founding editorial — “I will be heard” — establishes the uncompromising abolitionist position that reshaped antebellum reform movements.
    Whose story is missing?

    “I know that there are women in this land who would bear chains for the sake of peace. I know that there are women so in love with the tyrant Custom that for his sake they will be content to sit in the dust.” — Elizabeth Cady Stanton, address to the first women’s rights convention, Seneca Falls, 1848

    AP’s reform movements are usually taught through abolitionism, with women’s rights as a secondary current. But the Seneca Falls Convention and the Married Women’s Property Acts represented a separate mobilization challenging the legal non-existence of women as citizens and property-holders. Stanton’s Declaration of Sentiments—explicitly modeled on the Declaration of Independence—argued that the republic’s founding claims had excluded half its population from the start, and that recognizing this was not a reform but a correction. Read the source →

  • 5.6

    Reconstruction Politics & Constitutional Revolution

    The 13th, 14th, and 15th Amendments rewrote the Constitution — and the country undid most of it within a generation.ARC · PCE · NAT

    What to study

    Reconstruction (1865–1877) attempted to remake the South and integrate ~4 million newly freed people as citizens. Andrew Johnson’s lenient “Presidential Reconstruction” let ex-Confederates back into power and produced the Black Codes (1865) — laws restricting Black labor and movement. Congress responded with Radical Reconstruction: the Civil Rights Act (1866), the 14th Amendment (1868) guaranteeing equal protection, military occupation of the South, and the 15th Amendment (1870) guaranteeing Black male suffrage. Black Americans served in Congress (16 in this period), state legislatures (over 600), and local office across the South. The Supreme Court’s Slaughter-House (1873), Cruikshank (1876), and Civil Rights Cases (1883) gradually emptied the 14th Amendment of meaning. The Compromise of 1877 ended federal occupation in exchange for Hayes’s electoral victory; “Redemption” — the violent white Southern restoration — followed.

    Key termsBlack Codes · 13th, 14th, 15th Amendments · Radical Republicans · Freedmen’s Bureau · Sharecropping · Ku Klux Klan · Slaughter-House Cases · Compromise of 1877 · Redemption
    Exam focusAP graders reward essays that hold BOTH halves: the constitutional achievements (13/14/15 are still there) AND the violent reversal (Jim Crow took 80 years to undo). One-sided essays lose points.
    Primary sourceFrederick Douglass, What the Black Man Wants, 1865 — Digital History, University of Houston
    Douglass argues Black men need the ballot above all else — the clearest statement of what Reconstruction must accomplish and what its failure would cost.
    Whose story is missing?

    “The work of the abolitionists is not done. We have given the freedman the ballot, but we have not given him the land. Without land, the ballot is a mockery.” — Thaddeus Stevens, Radical Republican congressman, 1867

    Reconstruction’s constitutional revolution—the 13th, 14th, and 15th Amendments—is central AP content, but the amendments’ failure to accompany legal rights with economic foundation explains their reversal. Thaddeus Stevens’s push for land redistribution (“forty acres”) was defeated, leaving freedpeople legally free but economically dependent on the same planters who had enslaved them. AP students rarely ask why the Amendments were undone so quickly; the answer begins with what Reconstruction didn’t do as much as what it did. Read the source →

If the Civil War answered the question of whether slavery would survive, Reconstruction asked — and failed to answer — what kind of country we would be without it.— Lecture note, Period 5

Connect to the bigger picture

Era: World of Empires / Modern World

APWH cross-links: 6.4 Global Economic Development; 6.7 Effects of Migration

Next: Period 6 — Industrial America

Practice the skill — LEQ

Practice LEQ stem.

Evaluate the extent to which Reconstruction (1865–1877) marked a significant turning point in the political and social status of African Americans.Practice in the LEQ Lab