Abraham Lincoln's election in 1860 triggered a cascade of Southern secessions and the formation of the Confederacy, culminating in the Confederate attack on Fort Sumter in Charleston, South Carolina.

Abraham Lincoln's victory in 1860 sparked Southern secession—even before his inauguration

Abraham Lincoln's election on an antislavery expansion platform convinced many Southerners that their way of life was under threat. Within three months, seven states seceded from the Union—forming the Confederacy—before Lincoln took office in March 1861.

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.

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

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.

View animated battle maps from every major skirmish of the American Civil War.

Was the Civil War really about states' rights?

The Civil War was fought over slavery, and Confederate leaders and supporters admitted as much in the build-up to the war and after. But later on, after the South's defeat, the lie of the Lost Cause was pushed—and it persists to this day. This four-minute video details the story of the Lost Cause, "state's rights", Confederate monuments, and the machinations behind them.

The South was placed under federal military rule during Reconstruction

Beginning in 1867, the Reconstruction Acts divided 10 former Confederate states into five military districts, each governed by a Union general. Federal troops supervised elections, enforced civil rights, and maintained order under direct congressional authority.

One of the earliest Memorial Day ceremonies was held by newly freed Black Americans in South Carolina

On May 1, 1865, roughly 10,000 people, mostly freed slaves, paraded around a Charleston racetrack where Union prisoners had been buried, predating the first national commemoration at Arlington National Cemetery by three years.

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.

Hear how the world reacted to the American Civil War

European nations closely watched the Civil War for its economic and political consequences. Some European nations quietly engaged diplomatically with the Confederacy but withheld recognition. When the Union made slavery's abolition a central cause, European public opinion turned sharply against the South.

The final shots of the Civil War were fired in the Arctic over 2 months after the South's surrender.

Lincoln was assassinated by a well-known actor, who originally planned to kidnap him

On April 14, 1865, actor John Wilkes Booth shot President Abraham Lincoln at Ford's Theatre in Washington, DC. Booth had initially conspired to kidnap Lincoln but turned to assassination after the Confederacy's defeat.

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.

Congress descended into fistfights, duels, and violence before the Civil War

In the decades before the Civil War, members of the United States Congress carried weapons, assaulted colleagues, and, in one case, a congressman killed another in a duel. The violence was driven largely by sectional conflict over slavery and foreshadowed the nation's descent into war.

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.

Most Confederate soldiers and leaders after the Civil War were pardoned

After surrender, most Confederate soldiers were pardoned and returned home, while leaders like Jefferson Davis faced short imprisonment. The South came under military occupation, Confederate money became worthless, and many former officers were barred from public office.

Where was the Civil War fought?

The Civil War is commonly described as a war between northern and southern US states, but where was the war actually fought? Watch this interactive map and timeline to see who fought who and when. Click on specific battles to learn more about each fight.

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

Radical Reconstruction began in response to the lenient policies of Andrew Johnson

In 1867, Congress passed the Reconstruction Acts—overriding Johnson's vetoes—placing the South under military rule and requiring new state constitutions, Black male suffrage, and ratification of the 14th Amendment before readmission.

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 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.

'Presidential Reconstruction' attempted rapid reunification with minimal federal oversight

Led by Andrew Johnson after Lincoln's death, Presidential Reconstruction (1865-67) quickly restored Southern governments through mass pardons and lenient terms, allowing ex-Confederates to regain power and pass Black Codes that restricted freedpeople's rights.

The Civil War introduced many technological advances to both society and warfare.

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.

The Prize Cases established that the president can respond to an attack without waiting for Congress to act

When Lincoln blockaded Confederate ports at the start of the Civil War without congressional authorization, the Supreme Court upheld his actions, ruling that a president does not initiate war by responding to an attack and need not wait for Congress when the nation is already under threat.

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 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.

Southern states enacted voting restrictions aimed at circumventing Reconstruction

After 1877, former Confederate states passed poll taxes, literacy tests, property requirements, and grandfather clauses to disenfranchise Black voters—restrictions that remained in place for nearly a century until the Voting Rights Act of 1965.

See the army generals who helped define the Civil War

Hear profiles of the Union and Confederate commanders whose choices defined the war's outcome—from Grant and Lee to Sherman, Jackson, and others. See how their actions, tactics, and skills shaped the Civil War.

Ulysses S. Grant's leadership proved decisive in victory—and shaped postwar America

Elevated to general-in-chief in 1864, Ulysses S. Grant unified the Union strategy and forced a Confederate surrender at Appomattox. Elected president in 1868, he worked to enforce Reconstruction laws and protect the civil rights of freed African Americans.

37 maps that explain the American Civil War

This collection of 37 maps tells the story of the American Civil War as well as any historical account. See how and where the war began and why, and where the major battles were fought. Discover how the North achieved victory and the many ways the war changed America forever.

Robert Smalls escaped slavery by piloting a stolen Confederate ship to freedom, then became an influential Black political leader during Reconstruction.

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.

The Union victory at Gettysburg marked a major turning point in the war

Fought July 1-3, 1863, the Battle of Gettysburg ended the Confederate invasion of the North. While the Union lost nearly 23,000 troops, its victory in one of America's most famous battles shifted the war's momentum decisively toward the North.

Lincoln's Gettysburg Address became one of the most famous speeches in American history

Delivered by Lincoln on Nov. 19, 1863, at the dedication of a national cemetery, the 272-word Gettysburg Address reframed the war as a struggle for equality. The speech would be cited as a moral touchstone for later movements such as women's suffrage and civil rights.

The election of 1868 cemented power and support for Radical Reconstruction

In the first presidential election after the Civil War, Republican Ulysses S. Grant defeated Democrat Horatio Seymour. President Andrew Johnson, deeply unpopular with both parties, was denied renomination. Grant's victory reflected Northern support for Reconstruction.

The abolitionist movement long predated the Civil War

Beginning in the late 18th century, abolitionists like Frederick Douglass, William Lloyd Garrison, and Sojourner Truth campaigned through newspapers, lectures, and political action to end slavery.

The Civil War turned the Continental Divide into an American symbol of identity

Historians argue that the boundary only became a celebrated American symbol in the 1860s, when Civil War-era leaders promoted a west-east geographic divide to replace the devastating north-south political divide, and that the term's use spiked after the transcontinental railroad crossed it in 1868.