AP U.S. History Semester 1 Vocab Units 1-5

Manifest Destiny (5.2)

Definition: Belief that the U.S. was destined by God to expand across the continent.

Significance: Motivated westward expansion, conflict with Native Americans, and war with Mexico.

Great American Desert (5.2)

Definition: Term used for the Great Plains before the 1840s.

Significance: Early belief that the region was unsuitable for farming; delayed settlement.

Oregon Territory (5.2)

Definition: Region jointly occupied by Britain and the U.S.

Significance: Became a major destination for settlers; helped fulfill Manifest Destiny.

“Fifty-Four Forty or Fight” (5.2)

Definition: Polk’s campaign slogan demanding full control of Oregon up to latitude 54°40'.

Significance: Pressured Britain; ended with peaceful compromise at the 49th parallel.

James K. Polk (5.2)

Definition: Expansionist president (1845–1849).

Significance: Oversaw the Mexican War, Oregon settlement, and major westward expansion.

Stephen Austin (5.2)

Definition: Leader of the first large group of American settlers in Texas under Mexican rule.

Significance: His colony grew and later pushed for Texan independence.

Sam Houston (5.2)

Definition: Texan military leader; first president of the Republic of Texas.

Significance: Led Texas to independence from Mexico.

Alamo (5.2)

Definition: Battle where Mexican forces killed Texan defenders.

Significance: Became a rallying cry (“Remember the A*****!”) for Texan independence.

Webster-Ashburton Treaty (1842) (5.2)

Definition: Settled U.S.-Canada border disputes with Britain.

Significance: Improved relations and secured northern boundaries.

Matthew C. Perry (5.2)

Definition: U.S. naval officer who opened Japan to trade in 1854.

Significance: Ended Japan’s isolation and expanded U.S. commercial influence.

Mexican-American War (5.3)

Definition: War between Mexico and the U.S. (1846–48).

Significance: U.S. gained huge western lands; intensified slavery debate.

Rio Grande (5.3)

Definition: Border claimed by the U.S. between Texas and Mexico.

Significance: Dispute over this border helped trigger the war.

Zachary Taylor (5.3)

Definition: General who led U.S. forces in northern Mexico.

Significance: War hero who later became president.

John C. Fremont (5.3)

Definition: Explorer who led the Bear Flag Revolt in California.

Significance: Helped secure California for the U.S.

Winfield Scott (5.3)

Definition: U.S. general who captured Mexico City.

Significance: His victories ended the war.

Treaty of Guadalupe Hidalgo (5.3)

Definition: Treaty ending the Mexican War.

Significance: Mexico ceded California and the Southwest; U.S. achieved “Manifest Destiny.”

Mexican Cession (5.3)

Definition: Land gained from Mexico including CA, NV, UT, AZ, NM.

Significance: Reignited the slavery expansion controversy.

Wilmot Proviso (5.3)

Definition: Proposal to ban slavery in lands taken from Mexico.

Significance: Failed, but intensified sectionalism.

Gadsden Purchase (5.4)

Definition: U.S. purchase of southern AZ/NM in 1853.

Significance: Allowed construction of a southern transcontinental railroad

Free-Soil Party (5.4)

Definition: Party opposing expansion of slavery into the West.

Significance: Early foundation of the Republican Party.

Popular Sovereignty (5.4)

Definition: Let settlers vote on the idea of whether slavery should be outlawed in their territory.

Significance: Led to violence in Kansas.

Zachary Taylor (5.4)

Definition: Free-Soil–leaning president elected in 1848.

Significance: Opposed expanding slavery into new territories.

Henry Clay (5.4)

Definition: Kentucky senator known as the “Great Compromiser.”

Significance: Engineered the Compromise of 1850.

Compromise of 1850 (5.4)

Definition: Clay’s plan admitting CA as free, strengthening the Fugitive Slave Law, and using popular sovereignty elsewhere.

Significance: Temporarily eased sectional tension.

Panic of 1857 (5.5)

Definition: Economic depression affecting Northern industry more than the South.

Significance: Reinforced Southern belief in the superiority of King Cotton.

Nativism (5.5)

Definition: Anti-immigrant sentiment.

Significance: Led to the rise of the Know-Nothing Party.

Tammany Hall (5.5)

Definition: NYC Democratic political machine.

Significance: Symbolized urban corruption and immigrant political power.

Fugitive Slave Law (1850) (5.5)

Definition: Required return of escaped enslaved people.

Significance: Outraged Northerners and increased abolitionist support.

Underground Railroad (5.5)

Definition: Secret network helping enslaved people escape.

Significance: Challenged Southern slaveholders and federal law.

Harriet Tubman (5.5)

Definition: Leader of the Underground Railroad.

Significance: Escorted hundreds to freedom; major abolitionist figure.

Uncle Tom’s Cabin (5.5)

Definition: Anti-slavery novel.

Significance: Intensified Northern opposition to slavery.

Harriet Beecher Stowe (5.5)

Definition: Author of Uncle Tom’s Cabin.

Significance: “The little lady who started the big war” (Lincoln).

Impending Crisis of the South (5.5)

Definition: Anti-slavery book arguing slavery hurt Southern whites.

Significance: Banned in the South; strengthened sectional tensions.

Sociology of the South (5.5)

Definition: Pro-slavery book defending slavery as beneficial.

Significance: Reflected Southern defense of the institution.

“Bleeding Kansas” (5.6)

Definition: Violent conflict over slavery in Kansas.

Significance: Preview of the Civil War.

Pottawatomie Creek Massacre (5.6)

Definition: John Brown’s murder of pro-slavery settlers.

Significance: Escalated sectional violence.

Lecompton Constitution (5.6)

Definition: Pro-slavery Kansas constitution.

Significance: Rejected; deepened Democratic Party split.

Stephen A. Douglas (5.6)

Definition: Senator promoting popular sovereignty; Lincoln’s rival.

Significance: Key figure in Kansas-Nebraska Act.

Kansas-Nebraska Act (5.6)

Definition: Allowed popular sovereignty in KS and NE; repealed Missouri Compromise.

Significance: Caused Bleeding Kansas; birth of Republican Party.

Know-Nothing Party (5.6)

Definition: Anti-immigrant, anti-Catholic party.

Significance: Brief but influential in the 1850s.

Republican Party (5.6)

Definition: Anti-slavery-expansion party formed in response to Kansas-Nebraska Act.

Significance: Lincoln’s party.

James Buchanan (5.6)

Definition: 15th president; tried to maintain peace.

Significance: His inaction worsened sectional tensions and failed to take decisive action on the growing crisis over slavery.

Dred Scott v. Sandford (1857) (5.6)

Definition: Supreme Court ruled African Americans not citizens; Congress couldn't ban slavery.

Significance: Outraged the North; huge step toward war.

Roger Taney (5.6)

Definition: Chief Justice authoring the Dred Scott decision.

Significance: His ruling intensified sectional crisis.

Lincoln-Douglas Debates (5.6)

Definition: Senate debates between Lincoln and Douglas.

Significance: Helped make Lincoln nationally famous.

Abraham Lincoln (5.6)

Definition: Illinois Republican; later 16th president.

Significance: Opposed expansion of slavery.

House-Divided Speech (5.6)

Definition: Lincoln’s warning that the U.S. could not remain half slave, half free.

Significance: Framed slavery as a moral crisis.

Sumner–Brooks Incident (5.6)

Definition: Southern congressman beat Northern senator Charles Sumner with a cane.

Significance: Symbol of extreme sectional violence.

John Brown (5.7)

Definition: Radical abolitionist.

Significance: His violence convinced Southerners they were unsafe in the Union.

Harpers Ferry (5.7)

Definition: Brown’s raid to start a slave rebellion.

Significance: Deepened sectional distrust.

Constitutional Union Party (5.7)

Definition: Party seeking to avoid secession by ignoring slavery.

Significance: Gained border-state support in 1860.

Crittenden Compromise (5.7)

Definition: Last attempt to compromise by extending Missouri Compromise line.

Significance: Rejected by Lincoln; secession continued.

Border States (5.7)

Definition: Slave states that stayed in the Union (MD, DE, KY, MO).

Significance: Crucial for Union victory.

Fort Sumter (5.7)

Definition: First battle of the Civil War.

Significance: United the North against rebellion.

Confederate States of America (5.8)

Definition: Government formed by seceding Southern states.

Significance: Fought against the Union in the Civil War.

Jefferson Davis (5.8)

Definition: President of the Confederacy.

Significance: Led the South during the Civil War.

Bull Run (5.8)

Definition: First major battle of the Civil War.

Significance: Showed war would be long and bloody.

Thomas “Stonewall” Jackson (5.8)

Definition: Skilled Confederate general.

Significance: Key commander in early Confederate victories.

Anaconda Plan (5.8)

Definition: Union strategy to blockade the South and control the Mississippi River.

Significance: Gradually suffocated the Confederacy.

George B. McClellan (5.8)

Definition: Cautious Union general.

Significance: Criticized for failing to aggressively attack.

Robert E. Lee (5.8)

Definition: Confederate general.

Significance: Brilliant tactician leading Confederate armies.

Antietam (5.8)

Definition: Bloodiest single day of the war.

Significance: Union victory allowed Lincoln to issue the Emancipation Proclamation.

Fredericksburg (5.8)

Definition: Major Confederate victory.

Significance: Demonstrated Union leadership weaknesses

Monitor vs. Merrimac (5.8)

Definition: First ironclad ship battle.

Significance: Revolutionized naval warfare.

Ulysses S. Grant (5.8)

Definition: Union general and later president.

Significance: Led Union to victory.

Shiloh (5.8)

Definition: Bloody battle in Tennessee.

Significance: Showed brutal nature of western campaigns.

Vicksburg (5.8)

Definition: Union siege capturing Mississippi stronghold.

Significance: Split the Confederacy.

Gettysburg (5.8)

Definition: Turning-point battle in the East.

Significance: Stopped Lee’s invasion; Union momentum.

Sherman’s March (5.8)

Definition: Union troop campaign destroying the South’s infrastructure.

Significance: Broke Southern morale.

William Tecumseh Sherman (5.8)

Definition: Union general behind the March to the Sea.

Significance: Pioneer of “total war.”

Appomattox Court House (5.8)

Definition: Site of Lee’s surrender to Grant.

Significance: End of the Civil War.

Pacific Railway Act (5.9)

Definition: Law funding the transcontinental railroad.

Significance: Connected and developed the West.

Homestead Act (1862) (5.9)

Definition: Granted 160 acres of free land to western settlers.

Significance: Encouraged westward migration.

Habeas Corpus (5.9)

Definition: Legal protection from unlawful arrest.

Significance: Suspended by Lincoln to detain Confederate sympathizers.

Confiscation Acts (5.9)

Definition: Allowed Union to seize Confederate property, including enslaved people.

Significance: Early steps toward emancipation.

Emancipation Proclamation (5.9)

Definition: Freed enslaved people in Confederate-held territories.

Significance: Shifted the war to a moral struggle; allowed Black enlistment.

Copperheads (5.9)

Definition: Northern Democrats opposing the war.

Significance: Challenged Lincoln’s policies.

Gettysburg Address (5.9)

Definition: Two-minute speech redefining the war as a fight for freedom and equality.

Significance: One of the most famous speeches in U.S. history.

Massachusetts 54th Regiment (5.9)

Definition: First major African American Union regiment.

Significance: Proved Black soldiers’ valor and helped win acceptance for Black troops.

13th Amendment (5.10)

Definition: Constitutional amendment (1865) that abolished slavery in the United States.

Significance: Formally ended legal slavery and transformed the labor system of the South.

Civil Rights Act of 1866 (5.10)

Definition: Law granting citizenship and equal protection to African Americans.
Significance: First U.S. law defining citizenship; aimed to overturn Black Codes.

14th Amendment (5.10)

Definition: Guaranteed citizenship, due process, and equal protection under the law.
Significance: Most important amendment for civil rights and court decisions & overturned Dred Scott.

15th Amendment (5.10)

Definition: Prohibited denying voting rights based on race, color, or previous conditions of servitude. 

Significance: Gave Black men the right to vote (in theory).

Civil Rights Act of 1875 (5.10)

Definition: Guaranteed equal accommodations in public places.
Significance: Last major Reconstruction civil rights law; later overturned by Supreme Court (1883).

Jay Gould (5.10)

Definition: Railroad speculator known for corrupt financial schemes.
Significance: Example of Gilded Age corruption.

Credit Mobilier (5.10)

Definition: Scandal where Union Pacific executives created a fake company to steal railroad funds.
Significance: Damaged trust in government and Grant’s administration.

William “Boss” Tweed (5.10)

Definition: Political boss of NYC’s Tammany Hall.
Significance: Symbol of urban political corruption.

Thomas Nast (5.10)

Definition: Political cartoonist who exposed corruption.
Significance: Helped take down Boss Tweed through cartoons.

Panic of 1873 (5.10)

Definition: Severe economic depression caused by overbuilding and rail speculation.
Significance: Hurt Northern support for Reconstruction.

Proclamation of Amnesty and Reconstruction (5.10)

Definition: Lincoln’s plan offering leniency to Southern states that rejoined the Union (10% Plan).
Significance: Aimed for quick, moderate Reconstruction; included Oath of loyalty.

Wade-Davis Bill (5.10)

Definition: Radical Republican Reconstruction plan requiring 50% loyalty oath.
Significance: Much stricter than Lincoln’s plan; Lincoln pocket-vetoed it.

Andrew Johnson (5.10)

Definition: President after Lincoln; lenient toward South.
Significance: Clashed with Congress; impeached (but not removed) & vetoed Freedmen’s Bureau, opposed civil rights laws, and supported Black Codes indirectly.

Freedmen’s Bureau (5.10)

Definition: Agency providing aid to freed slaves and refugees.
Significance: Most successful Reconstruction program & established schools and offered food and legal support

Radical Republicans (5.10)

Definition: Congressional group pushing for strict Reconstruction and Black rights.
Significance: Passed major civil rights amendments.

Charles Sumner (5.10)

Definition: Leading Radical Republican in the Senate.
Significance: Championed Black civil rights.

Thaddeus Stevens (5.10)

Definition: Radical leader in the House of Representatives.
Significance: Strong supporter of land redistribution and punishment of Confederates.

Reconstruction Acts (5.10)

Definition: Laws dividing the South into military districts and requiring new constitutions.
Significance: Enforced civil rights and ensured Black suffrage

Tenure of Office Act (5.10)

Definition: Law restricting presidential power to remove officials.
Significance: Used as basis for Johnson’s impeachment.

scalawags (5.10)

Definition: Southern whites who supported Reconstruction.
Significance: Viewed as traitors by other Southerners.

carpetbaggers (5.10)

Definition: Northerners who moved South after the Civil War.
Significance: Some sought opportunity; others helped reform.