The causes of the American Civil War are found in a complex blend of political, economic, social and psychological factors — all overshadowed by the massive specter of slavery.
In the early 19th century, slavery appeared to be in decline, but a series of events worked to revive the institution, including:
The Nat Turner rebellion of 1831, which generated widespread fear of slave uprisings in the South and ended support for emancipation; Southerners were leery of living with freed blacks
The revival of the cotton economy occurred with the invention of the cotton gin and as new areas in the Deep South were brought under cultivation; cotton production again became profitable, renewing the demand for slavery
The attacks of Northern abolitionists may have rallied Northern anti-slavery forces, but they offended many Southerners, slaveowners and non-slaveowners alike; Southern sensibilities were further irritated by attacks from Northern clergymen, newspaper editors and authors, particularly Harriet Beecher Stowe
It must be remembered that there was no unanimity of opinion on slavery within either the South or the North.
The vast majority of white Southerners were too poor to own slaves and were in the difficult position of having to compete against unpaid labor. This triggered a mass migration of independent farmers who sought new opportunities farther west. The poor whites who remained in the South were not inclined to defend slavery, unless they felt that their culture was under attack from outside.
The political representatives of the Southern plantation society were of course the primary advocates of slavery. They went to some lengths to justify slavery and counter the arguments made against them in the North. While speaking frequently in moral terms, the Southern planters realized that the plantation system would wither and die without slavery. The “fire-eaters" were hotheaded Southerners who defended slavery and preached secession; prominent within that category were Robert A. Toombs, Robert B. Rhett, and William L. Yancey.
Southern voices expressing a negative view of the impact of slavery upon local workers were rare; the most prominent critic was Hinton R. Helper.
This situation was not without a parallel in the North. There the largest part of the population was composed of farmers and tradespeople, few of whom had any direct exposure to slavery. Their root concern was economic, not moral. They did not want to compete against slave labor and did not want the new western lands committed to giant plantations. The Northern workers were willing to tolerate slavery as it existed in the Southern states, but opposed its spread into the territories.
The Northern abolitionists, however, opposed the spread of slavery into the territories and also wanted to abolish its existence in the Southern states. If the destruction of slavery meant the end of the plantation system and resulting economic turmoil, then so be it. Albeit a small minority of Northern opinion, the abolitionists were nevertheless persistent and vocal, fired by their certainty that slavery was a moral wrong. These views were expressed by such prominent figures as William Lloyd Garrison, Henry Ward Beecher and the zealot John Brown. Political support came from the likes of Charles Sumner and Salmon P. Chase.
By the late 1850s, it appeared that two separate cultures had developed. Religious denominations, such as the Methodists and Baptists, split into independent Northern and Southern assemblies. College students withdrew from schools in a different section of the country and returned to ones closer to home.
The South was confident of the superiority of its ways of life. Plantation society romanticized the bygone English Cavalier days by reviving chivalry and staging jousting tournaments—a jarringly stark contrast to Northern society. The separation touched economic matters as well as social ones. Efforts were made to advance Southern shipping interests, e.g. the Southern route for a transcontinental railroad and a boycott of selected Northern goods—none of which met with much success.
The North looked down upon the South, noting its self-absorption and relative lack of prosperity. The North differed sharply from the South, however, in its willingness to admit to its shortcomings; there was no effort to try to romanticize Northern life. The Industrial Revolution had brought tremendous increases in wealth and technology, but it tended to concentrate in the pockets of a few. Factory work was impersonal and often dangerous; sweatshops and child labor were commonplace. Wealth was channeled to greedy politicians; contributions and bribes yielded protective tariffs and federal subsidies that were helpful to the moneyed interests of the North.