The Missouri Compromise temporarily eased tensions over slavery's expansion

The Compromise of 1850 tried to settle disputes over land gained from Mexico

Territory acquired in the Mexican-American War reignited fierce debates over slavery’s expansion. The Compromise of 1850 aimed to ease tensions by admitting California as a free state and letting other territories decide the issue—but the compromise ultimately failed and helped pave the way to the Civil War.

US westward expansion—and the status of slavery in the new territories—was a major cause of the American Civil War

The addition of new western lands forced the nation to confront whether slavery would spread beyond the South. Each debate over the admission of a new state sharpened the divide between free and slaveholding regions.

Mississippi didn't officially ratify the Thirteenth Amendment banning slavery until 2013, nearly 150 years after it passed.

The Kansas-Nebraska Act sparked violence that foreshadowed the Civil War

The 1854 Kansas-Nebraska Act let settlers vote on whether to allow slavery, repealing the Missouri Compromise. Competing proslavery and antislavery groups poured into Kansas, sparking years of bloody conflict known as "Bleeding Kansas."

The Lincoln-Douglas debates sharpened the national divide over slavery

In 1858, Abraham Lincoln and Senator Stephen Douglas debated while competing for an Illinois Senate seat. Their seven debates, reprinted nationwide, brought the question of slavery to the forefront—further polarizing the country and propelling Lincoln to national prominence.

The Constitution included compromises that still shape the US today

The creation of the Constitution necessitated numerous compromises to accommodate the diverse interests of the states. The significant compromises included resolutions on debates over representation in Congress and the status of enslaved individuals.

Madison urged Jefferson to accept the Louisiana Purchase despite constitutional concerns

As secretary of state, James Madison helped negotiate the 1803 Louisiana Purchase and persuaded Thomas Jefferson to proceed, arguing that the strategic and economic stakes outweighed the unresolved constitutional questions.

The 13th Amendment permanently abolished slavery in the United States

Ratified in December 1865, the 13th Amendment outlawed slavery nationwide except as punishment for a crime. Southern states were required to ratify it under President Andrew Johnson's initial Reconstruction plan before regaining representation, though Congress later imposed stricter conditions.

Lincoln's original reconstruction vision prioritized reconciliation

Proposed in 1863, Lincoln's Ten Percent Plan offered lenient readmission for Southern states once 10% of voters pledged loyalty and ended slavery. It was adopted in a few Union-occupied areas but was only partially implemented before his assassination in 1865.

The Compromise of 1790 broke a deadlock over debt and the national capital

In 1790, Alexander Hamilton, James Madison, and Thomas Jefferson reached an agreement that allowed Congress to assume the states' war debts and to approve a permanent national capital on the Potomac River.

A section condemning slavery was cut from the Declaration

Thomas Jefferson included a passage in his original draft denouncing slavery. This explainer from the Henry Ford Museum explores why Congress removed it to preserve colonial unity and how that decision shaped the nation's earliest political compromises.

The 1783 peace treaty with Britain formally ended the Revolutionary War and nearly doubled the size of the United States.

Congress's Wade-Davis Bill demanded harsher terms for Southern reentry

Passed in 1864, the Wade-Davis Bill required 50% of white male voters to swear loyalty and guarantee emancipation before readmission. Lincoln pocket-vetoed it, rejecting Congress's stricter approach.

Read an excerpt from the Monroe Doctrine, introduced in Monroe's 1823 address to Congress

On Dec. 2, 1823, President Monroe delivered his seventh annual message to Congress, now known as the State of the Union. One segment—warning European powers against interfering in the Western Hemisphere—became known as the Monroe Doctrine.

The Great Compromise created Congress's two-chamber structure during the Constitutional Convention

The Great Compromise of 1787 established a bicameral Congress, balancing population-based representation in the House with equal representation for each state in the Senate—a system designed to reconcile the competing interests of large and small states.

The Louisiana Purchase nearly doubled America’s size in 1803

Acquired from France for $15M, the Louisiana Purchase added 828,000 square miles to the United States—stretching from the Mississippi River to the Rockies. US ambassadors in France signed the papers to buy the tract from the embattled Napoleon Bonaparte for a mere $15M before Jefferson learned the terms, due to the advantageous nature of the deal.

Learn how Mexico’s anti-slavery stance shaped the US–Texas conflict

Historian Alice Baumgartner explores how Mexico’s abolition of slavery clashed with Anglo settlers' ambitions in Texas. The episode reveals how enslaved people fled south to freedom, reshaping the politics that led to Texas independence and the Mexican-American War.

Support for slavery helped drive Texas to revolt against Mexico

Mexico abolished slavery in 1829, but many Anglo-American settlers in Texas brought enslaved people and refused to comply. Their desire to preserve slavery was a major factor in Texas’s 1836 rebellion and independence from Mexico.

Despite the Juneteenth announcement that they were free, some enslaved people were still held captive.

A map of slavery's spread across the US

Need a visual on how prevalent slavery was in the US? Scroll through this interactive map and timeline based on census data from 1790 to 1860.

Missouri's nickname refers to its residents' skepticism

While the exact origins of the nickname are unclear, many attribute it to Congressman Willard Duncan Vandiver, who served in the United States House of Representatives from 1897 to 1903. In a 1899 speech, he said, "I come from a state that raises corn and cotton and cockleburs and Democrats, and frothy eloquence neither convinces nor satisfies me. I am from Missouri. You have got to show me."

Abraham Lincoln received only 40% of the popular vote in the 1860 election, highlighting the deep divisions in the country on the eve of the Civil War.

According to Confederate leaders, the defense of slavery was the primary reason for secession.

The Electoral College was shaped in part to balance North–South power

This article examines how the Electoral College emerged from political compromise, including efforts to placate slave-owning Southern states and concerns that Northern states would dominate a direct national presidential vote.

The nullification crisis tested whether states could defy federal law

In the 1830s, South Carolina declared federal tariffs void within its borders. President Andrew Jackson threatened military force, Congress passed a compromise tariff, and the episode ended with federal authority prevailing over state nullification.

The Emancipation Proclamation shifted the purpose of the war for the Union

Issued on Jan. 1, 1863, the Emancipation Proclamation declared enslaved people in Confederate-held territory free, redefining the Union's cause from merely preserving the nation to abolishing slavery.

The Reconstruction Amendments aimed to rebuild the nation and secure freedom after slavery

Ratified between 1865 and 1870 after the conclusion of the war, the 13th, 14th, and 15th Amendments abolished slavery, guaranteed citizenship and equal protection, and extended voting rights to Black men—transforming the Constitution's definition of liberty and equality.

How the US took half of Mexico

In just two years, the United States redrew the map of North America. Sparked by border disputes in Texas and fueled by President James Polk’s drive for expansion, the Mexican–American War (1846–1848) reshaped both nations.

The Dred Scott decision denied citizenship to people of African descent

In 1857, the Supreme Court ruled in Dred Scott v. Sandford that Black Americans could not be US citizens. The decision heightened an already brewing conflict and became a key factor in pushing the nation toward civil war.

11 states formed the Confederacy, with 2 others claiming allegiance

Between December 1860 and June 1861, 11 Southern states officially seceded to form the Confederacy. Pro-Confederate factions in Missouri and Kentucky also declared secession, but both states remained largely under Union control throughout the war.

Bills passed during the Civil War shaped postwar America

Despite the war with the South, Congress passed transformative laws like the Homestead Act and the Morrill Land-Grant College Act, which encouraged westward settlement and expanded higher education.

Slavery in the US: a timeline

In 1619, a ship with 20 captives landed at Point Comfort in Virginia, ushering in the era of American slavery. Scroll through this timeline to learn more about slavery in the US and its long lasting effects.

Missouri had the fastest job growth rate in 2025

Between 2024 and 2025, Missouri had a 1.7% job growth rate—representing the percent increase in jobs in a particular state over the course of a year. North Carolina and South Carolina trailed Missouri with annual job growth rates of 1.5% and 1.3% respectively.

James Monroe first outlined what became known as the 'Monroe Doctrine' during his 1823 Annual Message to Congress

President Monroe used his Annual Message to Congress to warn European powers against further colonization in the Western Hemisphere, asserting US opposition to foreign intervention and laying the foundation for a cornerstone of American foreign policy that remains to this day.

In the midst of the Civil War, Lincoln rapidly expanded presidential power

Abraham Lincoln suspended habeas corpus, expanded the army without congressional approval, and issued the Emancipation Proclamation—despite likely lacking authority to unilaterally alter national slave law. His actions set precedents for expanded presidential power in wartime.

A tense standoff with the Teton Sioux nearly ended the expedition

In 1804, the Teton Sioux seized a Corps of Discovery boat during a Missouri River meeting, sparking a dangerous standoff. The conflict eased only after careful diplomacy.

The Civil War permanently strengthened federal power

The Civil War expanded federal power through emancipation, national military mobilization, and postwar civil rights laws, permanently strengthening the national government and shifting the balance of authority away from the states.

The Treaty of Guadalupe Hidalgo forced Mexico to surrender over half its territory

Signed in 1848, the Treaty of Guadalupe Hidalgo ended the war but came at a steep cost for Mexico—ceding 55% of its territory, including California and the Southwest, in exchange for $15 million and vague promises to protect Mexican residents.

Mexico admired Lincoln for opposing the war and supporting Mexican sovereignty

As a congressman, Abraham Lincoln condemned the Mexican-American War as unjust. Years later, as president, he backed Mexico’s fight against French occupation. His principled stance earned enduring respect and monuments across Mexico.

The 13th Amendment's criminal exception enabled new forms of forced labor

Southern states exploited the amendment's clause allowing slavery "as punishment for crime" to arrest thousands of Black Americans on minor charges, leasing them to private employers through convict labor systems that persisted for decades.

3 states did not officially ratify the Bill of Rights until 1939

Massachusetts, Connecticut, and Georgia originally rejected or tabled the amendments in 1791. With Virginia's ratification already clearing the three-fourths threshold of adoption, there was no legal pressure to revisit it—until all three states acted symbolically on the 150th anniversary of Congressional approval of the amendments.

William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US.

A 1787 convention clash led to the creation of Congress’s two chambers

This article recounts debates on September 4, 1787, when delegates at the Constitutional Convention clashed over the balance of power between large and small states, driving the compromise that created the House and Senate.

Southern Black Codes sought to preserve prewar racial labor structures

With little federal oversight, Southern states enacted laws effectively reestablishing slavery's economic and social order. These laws, known as the "Black Codes," restricted freed people's movement, labor, and property rights.

Future President Abraham Lincoln challenged Polk’s justification for war with Mexico

As a freshman congressman, Abraham Lincoln introduced the “Spot Resolutions,” demanding President Polk prove that Mexico had attacked on US soil. This constituted Lincoln’s first major political stand and highlighted growing dissent over the war.

McCulloch v. Maryland upheld implied powers and blocked states from taxing the federal government

In 1819, McCulloch v. Maryland confirmed that Congress may use implied powers under the necessary and proper clause and ruled that states cannot tax federal institutions, reaffirming the supremacy of the federal government within its constitutionally delegated powers.

Jefferson feared European control in the West of North America

Jefferson pushed for the Louisiana Purchase to prevent France or Spain from dominating the western frontier, securing control of the Mississippi River and vast lands that he felt were essential to America’s strategic and economic future.

Later in life, Washington privately grew critical of slavery—while continuing to uphold it publicly

His private letters increasingly described slavery as unjust and incompatible with Republican ideals, and his final will ordered the eventual emancipation of those he legally owned. At the same time, he enforced slave labor, signed pro-slavery laws, and took no public action to dismantle the system.

The Indian Removal Act of 1830 forcibly displaced tens of thousands of Native Americans

Signed by President Andrew Jackson, the act authorized the federal government to negotiate treaties relocating Native nations from their Southeastern homelands to lands west of the Mississippi, often by force.

Madison condemned slavery in theory while owning slaves

James Madison argued that slavery violated Revolutionary ideals. Yet, he inherited and managed more than 100 enslaved people to operate the family's 3,000-acre plantation, brought enslaved laborers to the White House, and later sold them for personal profit.