The Civil War was an attempt of a geographical section of the United States to separate from the government. It was not a widespread class conflict stretched across the entire nation, or a conspiracy in the capital to seize power from the existing government. In order for there to be a geographical separatist movement there had to be a difference in the geographical sections of the country. That difference was slavery. It took approximately from 1786 to 1845 for the difference to occur. Northern states eliminated slavery. Some of them never permitted it, in keeping with the Northwest ordinance. Slavery expanded in some other states, due to the natural increase in the slave population, the legal and illegal importation of additional slaves, and the acquisition of additional territory in which slavery existed, especially the annexation of Texas. The difference in sections had underlying causes. The South was the nearly the optimal place in the world to grow the revolutionary new fiber, short staple cotton, and get it quickly and easily to a port where it could be shipped anywhere in the world. The south also had a difficult disease environment, which created a constant risk of diseases spread by insects and contaminated water. Cotton required large holdings of land to support the long rotation schedule necessary to allow the soil to recover. Plantations and small towns turned out to the best way to control disease events in the South. The large towns and cities of the United States existed in the north or on the edge of the Cotton region. Cotton could be grown in areas not subject to slavery, but it could not be produced a cost competitive with the price at which it could be produced in the south. It is possible to grow cotton without slavery. It was grown extensively in the United States without slavery after the Civil War. However, the amount of unskilled hand work necessary to maximize the harvest on a cotton field provided employment for slaves which was very profitable. Slave labor was actually free labor. The slaveowner did not have to pay cash wages for slave labor, though sometimes there were cash bonuses. Free labor is actually paid labor, because the employer almost always pays wages that allows the worker to live independently. The freedom associated with paid labor is almost never unqualified. The balance between work, free time and discretionary income is always contested in a paid labor economy. The essential difference was between slave labor and paid labor. Applying the word free to one type of labor simply meant that one type of laborer was allowed to vote, which changed the nature of society considerably. Paid laborers got to vote in the United States and slave laborers did not get to vote. In order for there to be a Civil War, the contesting sections have to independently viable. If one section is weak, it is probably going to submit to military force, or never begin the contest. In the case of the United States, had the secessionist states waited until the United States had completed the national railroad across the continent, most likely the northern coalition would have included Nebraska, Nevada and Colorado. At that point the North would have been too strong for the South to believe it could prevail. By 1860 there was a strong difference between the two sections, and each section felt confident it could sustain a military force. The preconditions existed among the population in the two sections, but that does not make secession and a Civil War probable or necessary. Individual people created the secessionist movement. The secessionist movement was a reaction to a populist movement. The populist movement transferred power to new people and new alliances, by democratic means. Individual people disapproved of this movement and the effect it would have on slavery. They thought that they could take advantage of the short history of democratic government, and the shortage of support of populist ideals in the United States and the world, to undo and avoid this transfer of power. Individual people seized on the secessionist rational, expanded it and convinced others that it justified their separatist coalition. 150 years later, as a sort of internet game, people still want to argue about secession. The people who had formed the populist movement then had a choice: they could let the opposition weaken their government and undermine their ideals, which had enormous short term advantages, or they could resort to war. Whatever we think of ourselves, war was typical of western European people in the centuries leading up the Civil War. The people of the United State had fought and won several wars, though they had never fought an adversary as dangerous as each other. The South did not secede. The South did not exist accept as a direction on the compass. Individual people created the idea of the South and advocated separation. Others agreed with them and took over the state governments in the secessionist states. The South as a short hand expression is widely understood, but conceals that secession was an experiment which was not unanimously supported. Individual people in the United States decided that disadvantages of conceding to secession were profound enough to justify war. The fact that they adhered to that decision after the cost of the was revealed is what makes the conclusion of the Civil War in the United States a surprise ending. Slavery was a necessary cause of the Civil War. No other difference was profound enough to create a dispute worth fighting over. But a good deal more is required to make the Civil War occur. The idea of national unity has to weaken and that has to advocated continuously and effectively by powerful people.