Why Did the Civil War Start?

What did the seceding states say caused secession?

The clearest evidence comes from the people who left the Union. Four states, South Carolina, Mississippi, Georgia and Texas, published formal declarations explaining why they were seceding. All four put slavery at the center.

In their own official words, the first states to secede said they were leaving the Union to protect slavery.

State	Document	What it says (short quote)
South Carolina	Declaration of the Immediate Causes, December 24, 1860	Northern states "have denounced as sinful the institution of slavery"
Mississippi	Declaration of the Immediate Causes	"Our position is thoroughly identified with the institution of slavery"
Georgia	Declaration of causes, approved January 29, 1861	Complaints against the free states "with reference to the subject of African slavery"
Texas	Declaration of the Causes, February 2, 1861	Texas joined the Union "as a commonwealth holding, maintaining and protecting the institution known as negro slavery"

South Carolina's declaration objected to the election of a president "whose opinions and purposes are hostile to slavery" ^[1]. Mississippi's opened by calling slavery "the greatest material interest of the world" ^[2]. Georgia's complained that the North had tried "to deprive us of an equal enjoyment of the common Territories" ^[3]. Texas's accused twelve named states of violating the Constitution's fugitive slave clause ^[4].

Confederate leaders said the same thing in public. In Savannah, Georgia, on March 21, 1861, Confederate Vice President Alexander H. Stephens gave what became known as the Cornerstone Speech. He called slavery "the immediate cause of the late rupture and present revolution" and said the new government's "corner-stone rests" on the claim of racial inequality ^[5].

How did the fight over slavery in the West lead to war?

For forty years before the war, the sharpest national fight was over the western lands: would they become free states or slave states? Each answer changed the balance of power in Congress, and each compromise lasted only until the next crisis.

The Missouri Compromise (1820). Approved on March 6, 1820, it admitted Missouri as a slave state and Maine as a free state, keeping the balance even, and banned slavery in the rest of the Louisiana Territory north of 36°30' latitude ^[6].

The Compromise of 1850. A package of laws approved in September 1850 admitted California as a free state, let New Mexico and Utah territories decide on slavery for themselves, banned the slave trade (not slavery) in Washington, D.C., and passed a much tougher Fugitive Slave Act. That law commanded "all good citizens" to help capture people who had escaped slavery, and it barred the accused person's own testimony at hearings ^[7].

The Kansas-Nebraska Act (1854). Approved on May 30, 1854, Senator Stephen Douglas's law let settlers in Kansas and Nebraska decide on slavery by "popular sovereignty" and repealed the 1820 line. It "reopened the national struggle over slavery in the western territories," and the violent contest that followed became known as "Bleeding Kansas" ^[8].

Dred Scott v. Sandford (1857). On March 6, 1857, Chief Justice Roger B. Taney's majority opinion held that Black Americans whose ancestors had been enslaved were not citizens and that Congress had no authority to ban slavery from a federal territory ^[9]. The National Archives notes that the ruling made the Missouri Compromise unconstitutional ^[6].

Each attempt to settle slavery in the West lasted only until the next crisis, and after Dred Scott there was no compromise line left to defend.

Why did Lincoln's election lead to secession?

The 1860 election split four ways. On November 6, 1860, Abraham Lincoln of the new Republican Party won about 40 percent of the popular vote but 180 electoral votes, well above the 152 needed. He won 18 states, all of them free states, and no state where slavery was legal; some Southern states did not even print ballots for him ^[10]. John C. Breckinridge took 72 electoral votes, John Bell 39 and Stephen Douglas 12; Lincoln was not on the ballot in any Southern state ^[11].

Lincoln had long backed "free soil" policies, meaning slavery should not spread into new territories ^[10]. The Georgia declaration called a ban on slavery in the territories "the cardinal principle" of the Republican Party ^[3]. The National Park Service describes the result as a "sectional victory" that many Southerners saw as the final straw ^[12].

How did secession unfold, state by state?

Secession came in two waves. The first seven states, all in the Deep South, left before Lincoln took office. On February 4, 1861, they formed the Confederate States of America, with Jefferson Davis as president ^[12]. The four states of the Upper South stayed in the Union until after Fort Sumter.

Wave	States	When	What tipped them
First	South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana, Texas	December 20, 1860 to February 1, 1861	Lincoln's election
Second	Virginia, Arkansas, North Carolina, Tennessee	April 17 to June 8, 1861	Fort Sumter and Lincoln's call for troops

The secession dates in both waves come from the National Park Service ^[12]. Texas's convention acted on February 1, 1861, and adopted its declaration of causes on February 2 ^[4].

What happened at Fort Sumter?

Fort Sumter sat on an island in Charleston Harbor, South Carolina, and was still held by a small U.S. Army garrison under Major Robert Anderson. Confederate Brigadier General P.G.T. Beauregard commanded the forces around the harbor. At 4:30 a.m. on April 12, 1861, a signal shot opened the Confederate bombardment. Anderson lowered the flag at 2:30 p.m. on April 13, and the garrison left the fort on April 14. About 80 Union soldiers faced about 500 Confederates, and the bombardment itself killed no one ^[13]. The National Park Service calls these "the first shots of the Civil War" ^[14].

On April 15, Lincoln called for 75,000 volunteers "to suppress the rebellion." Two days later Virginia voted 88 to 55 to secede, and the call angered the other Upper South states that had not yet left, North Carolina, Tennessee and Arkansas ^[15]. With eleven states in the Confederacy, a political crisis had become a war.

Was the Civil War about states' rights?

The short answer from the documents is: states' rights to what? When the seceding states talked about rights, the right they named again and again was the right to hold people in slavery and to take that system into the territories.

The declarations also show a twist. South Carolina complained that Northern states "have enacted laws which either nullify the Acts of Congress or render useless any attempt to execute them," meaning laws that blocked the return of people who had escaped slavery ^[1]. Texas objected that free states had punished their own citizens and officers for enforcing the fugitive slave clause ^[4]. In other words, the seceding states were protesting Northern states using their own powers against slavery, and they wanted the federal government to enforce slavery more strongly, not less. The Texas declaration does not use the phrase "states' rights" at all; it speaks of "the rights of the slave-holding States in their domestic institutions" ^[4].

What is the "Lost Cause"?

After the war, a different story took hold. The American Battlefield Trust describes the "Lost Cause" as a myth whose first claim was that secession was about states' rights and self-government, not slavery. Its other claims included that slavery had been benign, that the Confederacy lost only because the North had more men and factories, and that Confederate leaders such as Robert E. Lee deserved near-sainthood. Former Confederates promoted it through the Southern Historical Society, founded in 1869, and Jubal Early became its most influential voice; many Northerners accepted it for the sake of reconciliation ^[16].

Historians have rejected that account because it does not match the record of 1860 and 1861. Writing for the National Park Service, historian James Oliver Horton concludes that "slavery was central to the motivation for secession and war" ^[17]. Historians still discuss many questions about the war, including why ordinary soldiers enlisted and how Northern war aims changed, but the reason the Deep South seceded is not one of the open questions: the seceding states wrote it down.

The war that began at Fort Sumter ended slavery, a story that continues with the history of Juneteenth, and it cost Lincoln his life, as told in how many presidents have been assassinated. Americans who died in the war are remembered on Memorial Day. You can see where Lincoln falls among the U.S. presidents in order, explore our Civil War era guide, compare this with why World War I started, or browse more questions about why history happened. Our editorial policy explains how we check dates and sources.