Status of the states, 1861.

States that seceded before April 15, 1861

States that seceded after April 15, 1861

Union states that permitted slavery

Union states that banned slavery

Territories

Sectionalism refers to the different economies, social structure, customs and political values of the North and South.^[48][49] It increased steadily between 1800 and 1860 as the North, which phased slavery out of existence, industrialized, urbanized and built prosperous farms, while the deep South concentrated on plantation agriculture based on slave labor, together with subsistence farming for the poor whites. The South expanded into rich new lands in the Southwest (from Alabama to Texas).^[50]

However, slavery declined in the border states and could barely survive in cities and industrial areas (it was fading out in cities such as Baltimore, Louisville, and St. Louis), so a South based on slavery was rural and non-industrial. On the other hand, as the demand for cotton grew, the price of slaves soared. Historians have debated whether economic differences between the industrial Northeast and the agricultural South helped cause the war. Most historians now disagree with the economic determinism of historian Charles Beard in the 1920s and emphasize that Northern and Southern economies were largely complementary. While socially different, the sections economically benefited each other.^[51][52]

Fears of slave revolts and abolitionist propaganda made the South militantly hostile to abolitionism.^[53][54] Southerners complained that it was the North that was changing, and was prone to new "isms", while the South remained true to historic republican values of the Founding Fathers (many of whom owned slaves, including Washington, Jefferson, and Madison). Lincoln said that Republicans were following the tradition of the framers of the Constitution (including the Northwest Ordinance and the Missouri Compromise) by preventing expansion of slavery.^[55]

In the 1840s and 50s, the issue of accepting slavery (in the guise of rejecting slave-owning bishops and missionaries) split the nation's largest religious denominations (theMethodist, Baptist and Presbyterian churches) into separate Northern and Southern denominations.^[56] Industrialization meant that seven European immigrants out of eight settled in the North. The movement of twice as many whites leaving the South for the North as vice versa contributed to the South's defensive-aggressive political behavior.^[57]

Protectionism

Main articles: King Cotton, Protectionism in the United States and Infant industry

New Orleans the largest cotton exporting port for New England and Great Britain textile mills, shipping Mississippi River Valley goods from North, South and Border states.

Historically, southern slave-holding states, because of their low cost manual labor, had little perceived need for mechanization, and supported having the right to sell cotton and purchase manufactured goods from any nation. Northern states, which had heavily invested in their still-nascent manufacturing, could not compete with the full-fledged industries of Europe in offering high prices for cotton imported from the South and low prices for manufactured exports in return. Thus, northern manufacturing interests supported tariffs and protectionism while southern planters demanded free trade.^[58]

The Democrats in Congress, controlled by Southerners, wrote the tariff laws in the 1830s, 1840s, and 1850s, and kept reducing rates so that the 1857 rates were the lowest since 1816. The South had no complaints but the low rates angered Northern industrialists and factory workers, especially in Pennsylvania, who demanded protection for their growing iron industry. The Whigs and Republicans complained because they favored high tariffs to stimulate industrial growth, and Republicans called for an increase in tariffs in the 1860 election. The increases were finally enacted in 1861 after Southerners resigned their seats in Congress.^[59][60]

Historians in the 1920s emphasized the tariff issue but since the 1950s they have minimized it, noting that few Southerners in 1860–61 said it was of central importance to them. Some secessionist documents do mention the tariff issue, though not nearly as often as the preservation of slavery.