Key takeaways
- Wikipedia states that historians in the 21st century overwhelmingly agree on the centrality of slavery to the conflict.
- The fight over whether new western territory would be slave or free ran through the Missouri Compromise, the Compromise of 1850 and the Kansas–Nebraska Act of 1854.
- South Carolina's own declaration of 24 December 1860 cites hostility to slavery and the election of a president 'whose opinions and purposes are hostile to slavery'.
- Lincoln won 180 of 303 electoral votes in 1860 with about 40% of the popular vote, carrying the North.
- The war began on 12 April 1861 with the Confederate bombardment of Fort Sumter in Charleston harbour.
The central cause of the American Civil War was slavery — specifically, the Southern states' determination to preserve it and to extend it into new western territory. Wikipedia's article on the war's origins states that historians in the 21st century "overwhelmingly agree on the centrality of slavery," while still debating why the North refused to let the South go. It also quotes a 2011 panel of historians that draws the distinction neatly: slavery and its discontents were "the primary cause of disunion," but "it was disunion itself that sparked the war."
This page follows that chain from the 1820s to Fort Sumter, and shows what the secessionists themselves wrote.
A balance that expansion kept breaking
Wikipedia describes slavery as prevalent in the United States from its founding in 1776 until 1865, predominantly in the South. It notes that the Constitution of 1787 ended up with both proslavery and antislavery features, and that the country's rapid territorial expansion kept raising the same question: would each new territory be slave or free?
In 1819, with Alabama's admission, there were 11 slave states and 11 free states. Missouri's application threatened that balance in the Senate. The Missouri Compromise admitted Missouri as a slave state and Maine as a free one, and banned slavery in the Louisiana Purchase north of 36°30′. Jefferson called the crisis "a fire bell in the night."
The Mexican War reopened the question. Wikipedia describes the Compromise of 1850 as admitting California as a free state, letting Utah and New Mexico decide for themselves, and giving the South a stronger Fugitive Slave Act — a law that, in Eric Foner's words quoted there, "could hardly have been designed to arouse greater opposition in the North."
1854–1859: the compromises collapse
The Kansas–Nebraska Act of 1854, Stephen Douglas's bill, let territorial legislatures decide "all questions pertaining to slavery," effectively repealing the Missouri line. Wikipedia records a firestorm of protest in the North; the Republican Party was founded the same year. The result in Kansas was violence and a pro-slavery Lecompton Constitution that Wikipedia says came out of massive vote fraud.
In 1857 the Supreme Court's Dred Scott decision, written by Chief Justice Roger Taney, held that Black Americans had "no rights which the white man was bound to respect" and that slavery could spread into the territories even if most of their people were anti-slavery. In October 1859 John Brown seized the federal arsenal at Harpers Ferry hoping to start a slave uprising; he was hanged by Virginia, and Wikipedia notes he was vilified in the South and celebrated by many Northern abolitionists as a martyr.
Behind the politics sat money. Wikipedia cites the secessionist William Lowndes Yancey, who in October 1860 put the value of Southern-held slaves at $2.8 billion.
The 1860 election, by the numbers
Lincoln ran as an opponent of extending slavery into the territories. The result, as Wikipedia lists it:
| Candidate | Electoral votes | Popular vote |
|---|---|---|
| Abraham Lincoln | 180 | 40% |
| John C. Breckinridge | 72 | 18% |
| John Bell | 39 | 13% |
| Stephen A. Douglas | 12 | 30% |
The electoral votes total 180 + 72 + 39 + 12 = 303, so a majority was 152. Lincoln's 180 is 59.4% of the electoral college, won with 40% of the popular vote — and Wikipedia adds that he was not even on the ballot in ten Southern states. Wikipedia notes that the Southern states as a group had fewer electoral votes than the rapidly industrialising North, so a candidate could now win the presidency on Northern votes alone.
What the secession documents say
South Carolina's convention declared the Union dissolved, and on 24 December 1860 it issued a declaration of causes, transcribed by Yale's Avalon Project. It complains of "an increasing hostility on the part of the non-slaveholding States to the institution of slavery," of states that had "denounced as sinful the institution of slavery," and of their uniting "in the election of a man to the high office of President of the United States, whose opinions and purposes are hostile to slavery." Mississippi, Wikipedia notes, declared that its position was "thoroughly identified with the institution of slavery."
By February 1861 six more cotton states — Mississippi, Florida, Alabama, Georgia, Louisiana and Texas — had followed, forming the Confederate States of America. Wikipedia cites Seymour Martin Lipset's study of the secession vote: 72% for secession in high-slavery counties, 60% in middle counties and 37% in low-slavery counties. Reading the declarations as primary sources is the quickest way to test the claim that the war was "really" about something else.
States' rights and the Lost Cause
Wikipedia states that the consensus among historians is that the war was not fought about states' rights, though the idea has traction in popular accounts. James M. McPherson's point is that, even where Confederates invoked states' rights, it came down to a state's right to slavery. The Lost Cause ideology, which denies slavery was the principal cause, is described by Wikipedia as negationist and disproven by the secession documents — a useful case study in spotting bias in history writing.
The historians' debate has moved over time. Wikipedia describes 1920s–1940s "revisionists" such as James G. Randall, who blamed a "blundering generation" and saw the war as needless; later scholars, it notes, reject that view, and Shelden argues few would call it needless when the emancipation of 4 million enslaved people depended on Union victory.
From secession to Fort Sumter
Neither Buchanan nor Lincoln recognised secession, and the federal government refused to give up its forts in Confederate territory. On 12 April 1861 Confederate forces opened fire on Fort Sumter in Charleston harbour. Lincoln called for 75,000 militiamen, and Virginia, Tennessee, Arkansas and North Carolina then seceded.
The longer story of slavery and abolition across the Atlantic world is in the Atlantic slave trade and abolition, and the earlier American crisis over taxation in the causes of the American Revolution.
World History Timeline Sim, our app, lets you browse events by year and country to see 1820, 1850, 1854 and 1860 in sequence. Its Time Travel Mode offers what-if choices, and the listing is plain that those consequences are simulations, not history; it is meant to sit alongside coursework. More is collected under education and brain training.
Good to know
Frequently asked questions
Was the Civil War about slavery or states' rights?
What reasons did South Carolina give for seceding?
Why did Lincoln's election lead to secession before he took office?
What was the Lost Cause interpretation?
Sources
- Declaration of the Immediate Causes Which Induce and Justify the Secession of South Carolina from the Federal Union (opens in a new tab)The Avalon Project, Yale Law School — accessed
- Origins of the American Civil War (opens in a new tab)Wikipedia — accessed
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