Like most wars the cause was probably economics.  The industrailized North was charging the agricultural South more for the needed equipment than they could buy the same equipment overseas.  There were many more factors involved though.  Lifestyles were very different in the two sections.Also most of the Southern states believed that the individual states should govern themselves with just a loose union binding them together as a country.  The war changed that to the powerful central government we have today.Slavery was a factor surely but not the primary cause of the war.  Lincoln made a statement that if he could save the Union and free no slaves he would do so. If he could free the slaves and not save the Union he would not do so.

The cause of the Civil War was long in the making.? Henry Clay staved off the Civil War with the Missouri Compromise of 1820 and the Compromise of 1850.? Missouri was admitted as a slave state while Maine was admitted as a free state.? The Compromise of 1850 then undid the Missouri Compromise by allowing slavery in the New Mexico and Utah territories while forbidding it in California.? You can read up on Henry Clay here:? Wikipedia on Henry Clay.? Clay was also instrumental in helping to alleviate the Nullification Crisis that erupted in South Carolina (1828-1833) over Andrew Jackson's Tariff law.? Slavery as an institution did not actually cause the Civil War, but it's built in need to expand was at the root cause for the agitation between the North and the South.? Of course abolitionists like Lyman Beecher, Harriet Beecher Stowe, and Lloyd Garrison who published the abolitionist newspaper The Liberator kept the issue of slavery as an inflammatory topic.? Other events such as John Brown's Raid on Harper's Ferry, and the Nat Turner Rebellion sparked fear on the part of the South that forces were gathering momentum to foment massive slave insurrections.? One of the worst slave rebellions was the Stono Slave Rebellion in South Carolina in 1739.? Ever since Stono's Rebellion, the Southern planters became very fearful of mass slave insurrections.? As slavery became more and more ensconced in the Southern way of life, it became a "Peculiar Institution" where Southerners began to completely rearrange their morals and reasoning to justify chattel slavery.? In the end, this blind devotion to the Peculiar Institution forged such a paranoia, that when Abraham Lincoln was elected President in 1860, his allegiance to the new Republican Party with its connections to the Free Soil Party, pushed the South over the edge.? Southerners simply reacted out of fear and suspicion that Lincoln's ascension to power meant the certain end to their hallowed cultural institutions.? Of course their fears were unfounded, but to them, their fears were all that mattered.? Other factors contributing to the Civil War was the rapidity of industrial development witnessed by the North at the expense of the South.? Senator Stephen Douglas managed to get a transcontinental railway to run through the North via Chicago en route to California.? The rail system allowed Midwestern cities like Chicago to become a major hub for meat packing and commodities goods.? The North was already interlinked with railroads throughout the Northeast Corridor, while the South had only broken and disjointed rail systems between a few major cities including Richmond, Montgomery, Birmingham, Nashville, and Atlanta.? By 1860, the North was approximately 9 times the size of the South in terms of population, industrial output, and agricultural production.? The Confederate South was still the 5th largest industrial nation during the Civil War, but was entirely dwarfed by the North in comparison.? The South had steel production in Richmond and Birmingham, but nothing compared to the smelting foundaries of Pittsburgh and the rest of the North.? Culturally, the South began to resent the fact that most of their finished goods were being imported from the North.? Massachusetts textile mills were spinning the South's cotton into woven fabrics and clothes at several times the price of what the planters sold their cotton for.? Furthermore, cotton began to decline in price due to a serious glut on the open market throughout the mid-nineteenth century.? The Confederacy falsely believed it could "blackmail" the North with its prime cotton stores, but the North found other sources of cotton in India to keep its textile mills running.? This is also the reason England never entered on the side of the South, because it had its own source of cotton, and could benefit most by the North's blockcade of Confederate merchant ships.? The "Anaconda Plan" devised by General Winfield Scott, strangled the life out the Confederacy and contributed greatly to hastening the war's bitter conclusion.The issue of State's Rights was certainly important in the decision to go to war, but I think it was just another side component of the overall cultural resentment expressed by Southerners toward their Yankee brethren.? Yet oddly, it was Southerners who had arguably the most prominent hand in the crafting of the Constitution.? George Washington, Thomas Jefferson, James Madison, Elbridge Gerry, and Charles Pinckney were all Southerners who dominated the Constitution process.? Later it was Andrew Jackson, Henry Clay, and John C. Calhoun who shaped the government and held it together.? All of these Southerners believed in and fought courageously to keep the Union intact, but their efforts were soon forgotten once the Fire Eaters began their state by state campaign calling for secession conventions.? Yet at the end of the War, it was a Southerner who began the healing process as Tennessean Andrew Johnson (who became President after Lincoln's assassination) tried his best to expedite the Reconstruction of the South and to keep hawks like Thaddeus Stevens and Daniel Webster from exacting a greater revenge against the utterly defeated and destroyed recalcitrant states of the defunct Confederacy.? In the end, Johnson was impeached, but he managed to survive in office only to hand the dirty affair of reconstruction over to Ulysses S. Grant.? Grant's administration had to deal with the Ku Klux Klan (created by Nathan Bedford Forrest), and other vigilantes such as the Regulators in North Carolina.? Grant's cabinet was full of corrupt officials, all former cronies and friends of his, and because of this corruption, reconstruction was methodically taken over by the Southern states until Reconstruction ended after Grant left office.? The North won the Civil War, but they ultimately lost the peace as the South descended into a Share Cropping economy characterized by Jim Crow segregation that persisted until the 1960's.? Sectionalism still exists between the North and the South, and will likely continue for several more generations. 😥

Lincoln believed that the union was inviolable and indivisible.  There were many Southerners who agreed with him, and disliked the Confederacy vehemently.  Perhaps Lincoln feared that England or French Mexico would try and take advantage of a split United States.  Manifest Destiny may have played a role in the decision making process.  The West and the northern border with British Canada may have become a hotly contested piece of real estate.  I think Lincoln and William Seward were overtly desirous of American hegemony throughout North America.

As with most of mankinds decsions it's rarely about the people and more about the money. I believe Economics was more a factor for the war then was the simple truth that human beings should not be held in bondage. Most people in the south did not own slaves and many people in th north, though against slavery, did not feel the black man was their equal, regardless of his skill or education. There really was no noble cause for either side.