Compromise (1820‑1856)
This political label described mid-1800s efforts to avoid sectional conflict by keeping slavery out of national debate.
Popular sovereignty
This political party opposed the expansion of slavery and reshaped national politics along sectional lines.
Republican Party
This Union advantage proved decisive across the war, allowing sustained supply, production, and replacement of troops.
Industrial capacity
These Southern laws attempted to control Black labor and movement after emancipation, sparking Northern backlash.
Black Codes
This Supreme Court ruling weakened federal protection of civil rights by narrowing the meaning of national citizenship.
Slaughterhouse Cases
This war dramatically expanded U.S. territory and forced Congress to confront whether slavery would spread westward.
Mexican–American War
This 1859 event convinced many Southerners that abolitionists might use violence to destroy slavery.
John Brown’s raid on Harpers Ferry
This wartime law promoted western settlement and reflected the Republican vision of free-labor development.
Homestead Act
This reunification proposal allowed a former Confederate state to form a new government once a small minority of voters swore loyalty and accepted the end of slavery.
Ten Percent Plan
This Supreme Court decision allowed states to restrict voting as long as restrictions were not explicitly based on race.
United States v. Reese
This treaty mattered less for what it ended than for the national crisis it triggered over slavery’s expansion.
Treaty of Guadalupe Hidalgo
This split within a major political party made a sectional presidential election outcome almost inevitable.
Democratic Party split of 1860
This Confederate strategy relied on foreign dependence on Southern exports but collapsed once emancipation reshaped the war.
King Cotton diplomacy
This political event showed the depth of conflict between Congress and the president and helped define the limits of executive resistance.
Andrew Johnson’s impeachment
This Louisiana massacre showed how organized violence could overthrow Reconstruction governments at the local level.
Colfax Massacre
This influential novel intensified Northern antislavery sentiment by portraying slavery’s brutality to a mass audience.
Uncle Tom’s Cabin
After Lincoln’s election, these representatives traveled across the South spreading coordinated arguments for leaving the Union.
Secession commissioners
This 1863 uprising exposed class and racial tensions in the North and resistance to federal war policies.
New York City Draft Riots
This act divided the South into military districts, signaling Congress’s decision to remake Southern governments rather than quickly reconcile.
Reconstruction Act of 1867
This economic collapse shifted national focus away from civil rights enforcement toward financial recovery.
Panic of 1873
This proposed amendment sought to ban slavery in territory taken from Mexico but failed despite strong Northern support.
Wilmot Proviso
This series of 1858 debates forced national attention onto slavery by requiring candidates to publicly explain their positions.
Lincoln–Douglas Debates
This policy weakened the Confederacy by allowing formerly enslaved people to fight for the Union.
United States Colored Troops
This constitutional amendment made birthright citizenship national policy and required states to provide equal protection of the laws.
Fourteenth Amendment
This 1872 law restored political rights to most former Confederates, accelerating conservative control in the South.
Amnesty Act of 1872