APUSH Ch. 13 - Expansion, war, and sectional differences (1844-1860)

Manifest Destiny

An ideology embraced in the 1840s proclaiming a God-given duty for the U.S. to expand its republican institutions and Anglo-American culture across the continent to the Pacific Ocean. This expansionist drive led to conflicts over the Oregon Trail, war with Mexico, and the desire to acquire new territories like Cuba (see Ostend Manifesto).

Oregon Trail

The 2,000-mile route used by thousands of American migrants in the 1840s to reach the fertile lands of the Oregon Country and fulfill the vision of Manifest Destiny. The massive influx of settlers helped pressure the U.S. government to resolve the boundary dispute with Britain (see "Fifty-Four Forty or Fight").

Sioux

A powerful Native American nation on the Great Plains whose ancestral lands and way of life were directly threatened and disrupted by the massive influx of settlers traveling the Oregon Trail and the relentless push of Manifest Destiny.

“Young Hickory”

A nickname for President James K. Polk, elected in 1844, who was a protégé of Andrew Jackson ("Old Hickory"). A fervent expansionist, he fulfilled the goals of Manifest Destiny by aggressively settling the Oregon boundary (see "Fifty-Four Forty or Fight") and instigating the Mexican-American War to acquire the Mexican Cession (see Treaty of Guadalupe Hidalgo).

“Fifty-Four Forty or Fight”

The aggressive slogan adopted by expansionists and James K. Polk in the 1844 presidential election, demanding that the U.S. take control of the entire Oregon territory up to the latitude line of 54°40'. A compromise was eventually reached, establishing the 49th parallel as the boundary, allowing Polk to focus on war with Mexico.

John Slidell

A U.S. diplomat sent to Mexico by President Polk in 1845 to negotiate the purchase of California and New Mexico and settle the disputed border. Mexico’s refusal to receive him was used by Polk as a justification for declaring war, helping to achieve the territorial goals of Manifest Destiny via the Treaty of Guadalupe Hidalgo.

John C. Fremont

An American explorer and military officer who helped secure California during the Mexican-American War. After the war, he gained political prominence as the first presidential candidate for the anti-slavery Republican Party in 1856, symbolizing the shift of political power to those who opposed expansion of slavery.

Wilmot Proviso

A controversial 1846 proposal that sought to ban slavery in any territories acquired from Mexico as a result of the Mexican-American War and the Treaty of Guadalupe Hidalgo. Though it was approved by the House but blocked by the Senate, it intensified the sectional conflict and served as a foundation for the Free-Soil Movement.

Treaty of Guadalupe Hidalgo

The 1848 treaty that formally ended the Mexican-American War. In exchange for $15 million, Mexico ceded vast territories (the Mexican Cession), including California and New Mexico, to the U.S.. This territorial acquisition, driven by Manifest Destiny, immediately triggered a crisis over the expansion of slavery, addressed by measures like the Wilmot Proviso and the Compromise of 1850.

Free-Soil Movement

A political movement/party that emerged in 1848 in response to the land acquired from the Treaty of Guadalupe Hidalgo. Its core platform opposed the expansion of slavery into the western territories to protect opportunities for "free white labor." It opposed the doctrine that "Slavery Follows the Flag" and served as a crucial precursor to the Republican Party.

Frederick Douglass

An escaped former enslaved person, powerful orator, and prominent abolitionist. His autobiography and speeches exposed the brutality of slavery, fueling the anti-slavery sentiment that was later channeled into political opposition by the Free-Soil Movement and the Republican Party. He was a fierce opponent of the Fugitive Slave Act.

Zachary Taylor

A Whig General and hero of the Mexican-American War who was elected President in 1848. His push for California (rapidly populated by Forty-Niners) to be admitted immediately as a free state intensified the sectional crisis, which was only resolved after his death by the passage of the Compromise of 1850

Forty-Niners

The nickname given to the thousands of gold prospectors who flocked to California in 1849 following the discovery of gold there in 1848. This massive, rapid, and lawless population boom forced California's admission to the Union, bypassing the territorial stage, which created a crisis that necessitated the Compromise of 1850.

“Slavery Follows the Flag”

A Southern-supported doctrine arguing that the Constitution protected a slaveholder's property rights, allowing them to take enslaved people into any U.S. territory, regardless of local or federal law (like the Wilmot Proviso). This concept was vehemently opposed by the Free-Soil Movement and was later legally affirmed by the Dred Scott v. Sandford Supreme Court decision.

Popular Sovereignty

The political policy that allowed the residents of a territory, rather than Congress, to decide whether to permit slavery. Meant as a democratic solution to the sectional crisis over land from the Treaty of Guadalupe Hidalgo, it was championed by Stephen Douglas but ultimately failed, most dramatically leading to the violence in "Bleeding Kansas" under the Kansas-Nebraska Act.

Compromise of 1850

A legislative package intended to resolve the dispute over slavery in the Mexican Cession territories. It admitted California as a free state, organized the new territories under Popular Sovereignty, and enacted the highly controversial Fugitive Slave Act. Though it preserved the Union temporarily, the Fugitive Slave Act created deeper sectional resentment.

Fugitive Slave Act

The most divisive component of the Compromise of 1850. It required federal and state authorities to assist in the capture and return of runaway enslaved people, even those in free states. Northern opposition to this law—which made citizens complicit in slavery—intensified anti-slavery sentiment and spurred the growth of the Republican Party.

Ostend Manifesto

A secret 1854 diplomatic document urging the U.S. to purchase Cuba from Spain, threatening to seize it by force if Spain refused. This was an attempt by Southern expansionists, fueled by Manifest Destiny and the belief that "Slavery Follows the Flag," to acquire a new slave state. Its exposure led to a political outcry in the North, deepening the sectional divide.

Kansas-Nebraska Act

The 1854 law, pushed by Stephen Douglas, that repealed the Missouri Compromise and created the territories of Kansas and Nebraska, allowing settlers to decide the issue of slavery through Popular Sovereignty. This act was directly responsible for the massive civil unrest and violence in the region known as "Bleeding Kansas" and led to the formation of the Republican Party.

The Republican Party

A political party that formed in 1854 primarily in opposition to the Kansas-Nebraska Act. Drawing from the Free-Soil Movement and former Whigs, its core belief was that Congress had the right to prevent the expansion of slavery into the territories. Its rise signaled the collapse of the national party system and led to its eventual victory in the Election of 1860.

The Know-Nothing Party

The popular nickname for the American Party, which formed around 1851. It was primarily a nativist (anti-immigrant/anti-Catholic) party. It briefly gained support in the mid-1850s, but like the Democratic and Whig parties, it failed to maintain unity as the slavery issue—especially the violence in "Bleeding Kansas"—became the central focus of national politics, leading many members to join the Republican Party

“Bleeding Kansas”

A period of intense guerrilla warfare and bloodshed between pro-slavery and anti-slavery settlers in the Kansas Territory from 1854 to 1859. This violence was the direct result of the Kansas-Nebraska Act's implementation of Popular Sovereignty and proved that local self-determination could not peacefully resolve the national conflict over slavery. This period also launched the radical abolitionist actions of John Brown.

Dred Scott v. Sandford (1856)

The 1857 Supreme Court decision that ruled that enslaved or formerly enslaved people were not citizens and that Congress had no constitutional power to prohibit slavery in any territory. This ruling affirmed the Southern belief that "Slavery Follows the Flag" and invalidated the core anti-expansion platform of the Republican Party, greatly intensifying sectional tensions.

Lincoln-Douglas Debates

A series of high-profile debates held in 1858 between Republican Abraham Lincoln and Democrat Stephen Douglas (the champion of Popular Sovereignty). Though Douglas won the Senate seat, the debates elevated Lincoln to national prominence and exposed the deep divisions within the Democratic Party over slavery, setting the stage for the Election of 1860.

John Brown

A radical white abolitionist who believed violence was necessary to end slavery. He participated in the violence of "Bleeding Kansas" and is most famous for leading a failed raid on the federal armory at Harpers Ferry in 1859. His execution made him a martyr in the North and convinced many Southerners that the North was actively plotting slave revolts, pushing the nation closer to secession.

Election of 1860

The pivotal election where Abraham Lincoln, the candidate of the anti-expansion Republican Party, won the presidency in a four-way contest. The split of the Democratic Party allowed him to win with only Northern electoral votes. His victory was the final catalyst that led South Carolina and other Southern states to secede, triggering the Civil War.