The Slave Power (sometimes referred to as the "Slaveocracy") was a term used in the Northern United States (primarily in the period 1840–1875) to characterize the political power of the slaveholding class in the South.

The problem posed by slavery, according to many Northern politicians, was not so much the mistreatment of slaves (a theme that abolitionists emphasized), but rather the political threat to American republicanism, especially as embraced in Northern free states. The Free Soil Party first raised this warning in 1848, arguing that the annexation of Texas as a slave state was a terrible mistake. The Free Soilers rhetoric was taken up by the Republican party as it emerged in 1854.

The Republicans also argued that slavery was economically inefficient, compared to free labor, and was a deterrent to the long-term modernization of America. Worse, said the Republicans, the Slave Power, deeply entrenched in the "Solid South", was systematically seizing control of the White House, the Congress, and the Supreme Court. Senator and governor Salmon P. Chase of Ohio was an articulate enemy of the Slave Power, as was Senator Charles Sumner of Massachusetts.

In his celebrated "House Divided" speech of June 1858, Abraham Lincoln charged that Senator Stephen A. Douglas, President James Buchanan, his predecessor, Franklin Pierce, and Chief Justice Roger Taney were all part of a plot to nationalize slavery, as proven by the Supreme Court's Dred Scott decision of 1857.

Other Republicans pointed to the violence in Kansas, the brutal assault on Senator Sumner, attacks upon the abolitionist press, and efforts to take over Cuba (Ostend Manifesto) as evidence that the Slave Power was violent, aggressive, and expansive.

The only solution, Republicans insisted, was a new commitment to free labor, and a deliberate effort to stop any more territorial expansion of slavery. Northern Democrats answered that it was all an exaggeration and that the Republicans were paranoid. Their Southern colleagues spoke of secession, arguing that the John Brown raid of 1859 proved that the Republicans were ready to attack their region and destroy their way of life.

In congratulating President-elect Lincoln in 1860, Salmon P. Chase exclaimed, "The object of my wishes and labors for nineteen years is accomplished in the overthrow of the Slave Power", adding that the way was now clear "for the establishment of the policy of Freedom" — something that would come only after four destructive years of Civil War.

Everyone agreed that states had certain rights—but did those rights carry over when a citizen left that state? The Southern position was that citizens of every state had the right to take their property anywhere in the U.S. and not have it taken away—specifically they could bring their slaves anywhere and they would remain slaves. Northerners rejected this "right" because it would violate the right of a free state to outlaw slavery within its borders. Republicans committed to ending the expansion of slavery were among those opposed to any such right to bring slaves and slavery into the free states and territories. The Dred Scott Supreme Court decision of 1857 bolstered the Southern case within territories, and angered the North.

Secondly the South argued that each state had the right to secede—leave the Union—at any time, that the Constitution was a "compact" or agreement among the states. Northerners (including President Buchanan) rejected that notion as opposed to the will of the Founding Fathers who said they were setting up a "perpetual union". Historian James McPherson writes concerning states' rights and other non-slavery explanations:

While one or more of these interpretations remain popular among the Sons of Confederate Veterans and other Southern heritage groups, few professional historians now subscribe to them. Of all these interpretations, the state's-rights argument is perhaps the weakest. It fails to ask the question, state's rights for what purpose? State's rights, or sovereignty, was always more a means than an end, an instrument to achieve a certain goal more than a principle.

The balance of federal powers and those powers held by the states as defined in the Supremacy Clause of the U.S. Constitution was first addressed in the case of McCulloch v. Maryland (1819). Chief Justice John Marshall asserted that the laws adopted by the federal government, when exercising its constitutional powers, are generally paramount over any conflicting laws adopted by state governments. After McCulloch, the primary legal issues in this area concerned the scope of Congress' constitutional powers, and whether the states possess certain powers to the exclusion of the federal government, even if the Constitution does not explicitly limit them to the States.

Nationalism was a powerful force in the early 19th century, with famous spokesmen like Andrew Jackson and Daniel Webster. While practically all Northerners supported the Union, Southerners were split between those loyal to the entire United States (called "unionists") and those loyal primarily to the southern region and then the Confederacy. C. Vann Woodward said of the latter group, "A great slave society...had grown up and miraculously flourished in the heart of a thoroughly bourgeois and partly puritanical republic. It had renounced its bourgeois origins and elaborated and painfully rationalized its institutional, legal, metaphysical, and religious defenses....When the crisis came it chose to fight. It proved to be the death struggle of a society, which went down in ruins." Insults to Southern national honor included Uncle Tom's Cabin (1854) and John Brown in 1859.

Sectionalism refers to the different economies, social structure, customs and political values of the North and South. 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). 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.

Fears of slave revolts and abolitionist propaganda made the South militantly hostile to abolitionism. 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. The issue of accepting slavery (in the guise of rejecting slave-owning bishops and missionaries) split the largest religious denominations (the Methodist, Baptist and Presbyterian churches) into separate Northern and Southern denominations. 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

Slavery is one of the causes of American Civil War. Support for secession was strongly correlated to the number of plantations in the region. States of the Deep South, which had the greatest concentration of plantations, were the first to secede. The upper South slave states of Virginia, North Carolina, Arkansas, and Tennessee had fewer plantations and rejected secession until the Fort Sumter crisis forced them to choose sides. Border states had fewer plantations still and never seceded.

As of 1860 the percentage of Southern families that owned slaves has been estimated to be 43 percent in the lower South, 36 percent in the upper South and 22 percent in the border states that fought mostly for the Union. Half the owners had one to four slaves. A total of 8000 planters owned 50 or more slaves in 1850 and only 1800 planters owned 100 or more; of the latter, 85% lived in the lower South, as opposed to one percent in the border states.

Ninety-five percent of African-Americans lived in the South, comprising one third of the population there as opposed to one percent of the population of the North, chiefly in larger cities like New York and Philadelphia. Consequently, fears of eventual emancipation were much greater in the South than in the North.

The Supreme Court decision of 1857 in Dred Scott v. Sandford escalated the controversy. Chief Justice Roger B. Taney's decision said that slaves were "so far inferior that they had no rights which the white man was bound to respect". Taney then overturned the Missouri Compromise, which banned slavery in territory north of the 36°30' parallel. He stated, "The Act of Congress which prohibited a citizen from holding and owning enslaved persons in the territory of the United States north of the line therein is not warranted by the Constitution and is therefore void." Democrats praised the Dred Scott decision, but Republicans branded it a "willful perversion" of the Constitution. They argued that if Scott could not legally file suit, the Supreme Court had no right to consider the Missouri Compromise's constitutionality. Lincoln warned that "the next Dred Scott decision" could threaten Northern states with slavery.

Lincoln said, "This question of Slavery was more important than any other; indeed, so much more important has it become that no other national question can even get a hearing just at present." The slavery issue was related to sectional competition for control of the territories,^[32] and the Southern demand for a slave code for the territories was the issue used by Southern politicians to split the Democratic Party in two, which all but guaranteed the election of Lincoln and secession. When secession was an issue, South Carolina planter and state Senator John Townsend said that, "our enemies are about to take possession of the Government, that they intend to rule us according to the caprices of their fanatical theories, and according to the declared purposes of abolishing slavery." Similar opinions were expressed throughout the South in editorials, political speeches and declarations of reasons for secession. Even though Lincoln had no plans to outlaw slavery where it existed, whites throughout the South expressed fears for the future of slavery.

Southern concerns included not only economic loss but also fears of racial equality. The Texas Declaration of Causes for Secession said that the non-slave-holding states were "proclaiming the debasing doctrine of equality of all men, irrespective of race or color", and that the African race "were rightfully held and regarded as an inferior and dependent race". Alabama secessionist E. S. Dargan warned that whites and free blacks could not live together; if slaves were emancipated and remained in the South, "we ourselves would become the executioners of our own slaves. To this extent would the policy of our Northern enemies drive us; and thus would we not only be reduced to poverty, but what is still worse, we should be driven to crime, to the commission of sin."

Beginning in the 1830s, the US Postmaster General refused to allow mail which carried abolition pamphlets to the South. Northern teachers suspected of any tinge of abolitionism were expelled from the South, and abolitionist literature was banned. Southerners rejected the denials of Republicans that they were abolitionists. The North felt threatened as well, for as Eric Foner concludes, "Northerners came to view slavery as the very antithesis of the good society, as well as a threat to their own fundamental values and interests."

During the 1850s, slaves left the border states through sale, manumission and escape, and border states also had more free African-Americans and European immigrants than the lower South, which increased Southern fears that slavery was threatened with rapid extinction in this area. Such fears greatly increased Southern efforts to make Kansas a slave state. By 1860, the number of white border state families owning slaves plunged to only 16 percent of the total. Slaves sold to lower South states were owned by a smaller number of wealthy slave owners as the price of slaves increased.

Even though Lincoln agreed to the Corwin Amendment, which would have protected slavery in existing states, secessionists claimed that such guarantees were meaningless. Besides the loss of Kansas to free soil Northerners, secessionists feared that the loss of slaves in the border states would lead to emancipation, and that upper South slave states might be the next dominoes to fall. They feared that Republicans would use patronage to incite slaves and antislavery Southern whites such as Hinton Rowan Helper. Then slavery in the lower South, like a "scorpion encircled by fire, would sting itself to death."

The Abolitionist movement in the United States had roots in the Declaration of Independence. Slavery was banned in the Northwest Territory with the Northwest Ordinance of 1787. By 1804 all the Northern states had passed laws to abolish slavery. Congress banned the African slave-trade in 1808, although slavery grew in new states in the deep south. The Union was divided along the Mason Dixon Line into the North (free of slaves), and the South, where slavery remained legal. This is one of the causes of American Civil War.

Despite compromises in 1820 and 1850, the slavery issues exploded in the 1850s. Lincoln did not propose federal laws against slavery where it already existed, but he had, in his 1858 House Divided Speech, expressed a desire to "arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction." Much of the political battle in the 1850s focused on the expansion of slavery into the newly created territories. Both North and South assumed that if slavery could not expand it would wither and die.

Southern fears of losing control of the federal government to antislavery forces, and Northern resentment of the influence that the Slave Power already wielded in government, brought the crisis to a head in the late 1850s. Disagreements between Abolitionists and others over the morality of slavery, the scope of democracy and the economic merits of free labor versus slave plantations caused the Whig and "Know-Nothing" parties to collapse, and new ones to arise (the Free Soil Party in 1848, the Republicans in 1854, the Constitutional Union in 1860). In 1860, the last remaining national political party, the Democratic Party, split along sectional lines.

Northerners ranging from the abolitionist William Lloyd Garrison to the moderate Republican leader Lincoln emphasized Jefferson's declaration that all men are created equal. Lincoln mentioned this proposition many times, including his 1863 Gettysburg Address.

Almost all the inter-regional crises involved slavery, starting with debates on the three-fifths clause and a twenty-year extension of the African slave trade in the Constitutional Convention of 1787. The 1793 invention of the cotton gin by Eli Whitney increased by fiftyfold the quantity of cotton that could be processed in a day and greatly increased the demand for slave labor in the South. There was controversy over adding the slave state of Missouri to the Union that led to the Missouri Compromise of 1820. A gag rule prevented discussion in Congress of petitions for ending slavery from 1835–1844, while Manifest Destiny became an argument for gaining new territories, where slavery could expand. The acquisition of Texas as a slave state in 1845 along with territories won as a result of the Mexican–American War (1846–1848) resulted in the Compromise of 1850. The Wilmot Proviso was an attempt by Northern politicians to exclude slavery from the territories conquered from Mexico. The extremely popular antislavery novel Uncle Tom’s Cabin (1852) by Harriet Beecher Stowe greatly increased Northern opposition to the Fugitive Slave Law of 1850.

The 1854 Ostend Manifesto was an unsuccessful Southern attempt to annex Cuba as a slave state. The Second Party System broke down after passage of the Kansas-Nebraska Act in 1854, which replaced the Missouri Compromise ban on slavery with popular sovereignty, allowing the people of a territory to vote for or against slavery. The Bleeding Kansas controversy over the status of slavery in the Kansas Territory included massive vote fraud perpetrated by Missouri pro-slavery Border Ruffians. Vote fraud led pro-South Presidents Franklin Pierce and James Buchanan to attempt to admit Kansas as a slave state. Buchanan supported the pro-slavery Lecompton Constitution.

Violence over the status of slavery in Kansas erupted with the Wakarusa War, the Sacking of Lawrence, the caning of Republican Charles Sumner by the Southerner Preston Brooks, the Pottawatomie Massacre, the Battle of Black Jack, the Battle of Osawatomie and the Marais des Cygnes massacre. The 1857 Supreme Court Dred Scott decision allowed slavery in the territories even where the majority opposed slavery, including Kansas.

The Lincoln-Douglas debates of 1858 included Northern Democratic leader Stephen A. Douglas' Freeport Doctrine. This doctrine was an argument for thwarting the Dred Scott decision that, along with Douglas' defeat of the Lecompton Constitution, divided the Democratic Party between North and South. Northern abolitionist John Brown's raid at Harpers Ferry Armory was an attempt to incite slave insurrections in 1859. The North-South split in the Democratic Party in 1860 due to the Southern demand for a slave code for the territories completed polarization of the nation between North and South.

Causes of American Civil War

The American Civil War (1861–1865), among other names also known as the War Between the States, was a civil war in the United States of America. Eleven Southern slave states declared their secession from the United States and formed the Confederate States of America, also known as "the Confederacy". Led by Jefferson Davis, they fought against the United States (the Union), which was supported by all the free states (where slavery had been abolished) and by five slave states that became known as the border states.

In the presidential election of 1860, the Republican Party, led by Abraham Lincoln, had campaigned against the expansion of slavery beyond the states in which it already existed. In response to the Republican victory in that election, seven states declared their secession from the Union before Lincoln took office on March 4, 1861. Both the outgoing administration of President James Buchanan and Lincoln's incoming administration rejected the legality of secession, considering it rebellion. Several other slave states rejected calls for secession at this point.

Hostilities began on April 12, 1861, when Confederate forces attacked a U.S. military installation at Fort Sumter in South Carolina. Lincoln responded by calling for a volunteer army from each state to recapture federal property. This led to declarations of secession by four more slave states. Both sides raised armies as the Union assumed control of the border states early in the war and established a naval blockade. In September 1862, Lincoln's Emancipation Proclamation made ending slavery in the South a war goal, and dissuaded the British from intervening.

Confederate commander Robert E. Lee won battles in the east, but in 1863 his northward advance was turned back with heavy casualties after the Battle of Gettysburg. To the west, the Union gained control of the Mississippi River after their capture of Vicksburg, Mississippi, thereby splitting the Confederacy in two. The Union was able to capitalize on its long-term advantages in men and materiel by 1864 when Ulysses S. Grant fought battles of attrition against Lee, while Union general William Tecumseh Sherman captured Atlanta, Georgia, and marched to the sea. Confederate resistance collapsed after Lee surrendered to Grant at Appomattox Court House on April 9, 1865.

The American Civil War was one of the earliest true industrial wars. Railroads, steamships, mass-produced weapons, and various other military devices were employed extensively. The practices of total war, developed by Sherman in Georgia, and of trench warfare around Petersburg foreshadowed World War I in Europe. It remains the deadliest war in American history, resulting in the deaths of 620,000 soldiers and an undetermined number of civilian casualties. Ten percent of all Northern males 20–45 years of age died, as did 30 percent of all Southern white males aged 18–40. Victory for the North meant the end of the Confederacy and of slavery in the United States, and strengthened the role of the federal government. The social, political, economic and racial issues of the war decisively shaped the reconstruction era that lasted to 1877.

American Civil War
The Battle of Gettysburg
Date April 12, 1861 – April 9, 1865 (last shot ended June, 1865) Location Southern United States Result Union victory Territorial integrity of the United States of America preserved Reconstruction Slavery abolished
Belligerents
United States of America (Union)	Confederate States of America (Confederacy)
Commanders and leaders
Abraham Lincoln Winfield Scott George B. McClellan Henry Wager Halleck Ulysses S. Grant Gideon Welles and others	Jefferson Davis P.G.T. Beauregard Joseph E. Johnston Robert E. Lee Stephen Mallory and others
Strength
2,100,000	1,064,000
Casualties and losses
110,000 killed in action 360,000 total dead 275,200 wounded	93,000 killed in action 260,000 total dead 137,000+ wounded