The causes of the Civil War may be traced to a complex mix of factors, some of which can be traced back to the earliest years of American colonization. Principal among the issues was the following:
Causes of the Civil War: Slavery
Slavery in the United States first began in Virginia in 1619. By the end of the American Revolution, most northern states had abandoned the institution while it continued to grow and flourish in the plantation economy of the South. In the years prior to the Civil War almost all sectional conflicts revolved around the slave issue. This began with the debates over the three-fifths clause at the Constitutional Convention of 1787 and continued with the Compromise of 1820, the Nullification Crisis, the anti-slavery Gag Rule, and the Compromise of 1850.
Causes of the Civil War: Slavery and Control of the Government
Throughout the first half of the 19th century, Southern politicians sought to defend slavery by retaining control of the federal government. While they benefited from most presidents being from the South, they were particularly concerned about retaining a balance of power within in the Senate. As new states were added to the Union, a series of compromises were arrived at to maintain an equal number of "free" and "slave" states.
In 1820, Maine entered as a free state while Missouri joined as a slave state. The balance was finally disrupted in 1850, when Southerners permitted California to enter as a free state in exchange for laws strengthening slavery. This balance was further upset with the additions of free Minnesota (1858) and Oregon (1859).
Causes of the Civil War: Two Regions on Separate Paths
The widening of the gap between slave and free states was symbolic of the changes occurring in each region. While the South was devoted to an agrarian plantation economy with a slow growth in population, the North had embraced industrialization, large urban areas, infrastructure growth, as well as was experiencing high birth rates and a large influx of European immigrants. This boost in population doomed Southern efforts to maintain balance in the government as it meant the future addition of more free states and the election of a Northern, potentially anti-slavery, president.
Causes of the Civil War: Slavery in the Territories
The political issue that finally moved the nation towards conflict was that of slavery in the western territories won during the Mexican-American War. A similar issue had been dealt with earlier, in 1820, when, as part of the Missouri Compromise, slavery was permitted in the Louisiana Purchase south of 36°30'N latitude (the southern border of Missouri). Rep. David Wilmot attempted to prevent slavery in the new territories in 1846, when he introduced the Wilmot Proviso in Congress. After extensive debate it was defeated.
In 1850, an attempt was made to resolve the issue. A part of Compromise of 1850 called for slavery in the unorganized lands (largely Arizona & New Mexico) received from Mexico to be decided by popular sovereignty. This meant that the local people and their territorial legislatures would decide for themselves whether slavery would be permitted. Many thought that this decision had solved the issue until it was raised again in 1854 with the passage of the Kansas-Nebraska Act.
Causes of the Civil War: "Bleeding Kansas"
Proposed by Sen. Stephen Douglas of Illinois, the Kansas-Nebraska Act essentially repealed the line imposed by the Missouri Compromise. Douglas, an ardent believer in grassroots democracy, felt that all the territories should be subject to popular sovereignty. Seen as a concession to the South, the act led to an influx of pro- and anti-slavery forces into Kansas. Operating from rival territorial capitals, the "Free Staters" and "Border Ruffians" engaged in open violence for three years.
Though pro-slavery forces from Missouri had openly and improperly influenced elections in the territory, President James Buchanan accepted their Lecompton Constitution, and offered it to Congress for statehood. This was turned down by Congress which ordered a new election. In 1859, the anti-slavery Wyandotte Constitution was accepted by Congress. The fighting in Kansas further heightened tensions between North and South.
Causes of the Civil War: States' Rights
As the South recognized that control of the government was slipping away, it turned to a states' rights argument to protect slavery. Southerners claimed that the federal government was prohibited by the Tenth Amendment from impinging upon the right of slaveholders take their "property" into a new territory. They also stated that the federal government was not permitted to interfere with slavery in those states where it already existed. They felt that this type of strict constructionist interpretation of the Constitution coupled with nullification, or perhaps secession would protect their way of life.
Causes of the Civil War: Abolitionism
The issue of slavery was further heightened by the rise of the Abolitionist movement in the 1820s and 1830s. Beginning in the North, adherents believed that slavery was morally wrong rather than simply a social evil. Abolitionists ranged in their beliefs from those who thought that all slaves should be freed immediately (William Lloyd Garrison, Frederick Douglas) to those calling for gradual emancipation (Theodore Weld, Arthur Tappan), to those who simply wanted to stop the spread of slavery and its influence (Abraham Lincoln).
Abolitionists campaigned for the end of the "peculiar institution" and supported anti-slavery causes such as the Free State movement in Kansas. Upon the rise of the Abolitionists, an ideological debate arose with the Southerners regarding the morality of slavery with both sides frequently citing Biblical sources. In 1852, the Abolitionist cause received increased attention following the publication of the anti-slavery novel Uncle Tom's Cabin. Written by Harriet Beecher Stowe, the book aided in turning the public against the Fugitive Slave Act of 1850.Civil War 101 | Next: Opening Shots