There was nothing 'civil' about the Civil War. Neighbor fought neighbor and brother fought brother in a painful division between family and friends that mirrored the one between the North and the South. The Civil War started when between the Northern states (the Union) and the Southern states that seceded from the Union and formed the Confederacy.
During the 19th century the South remained almost completely agricultural, with an economy and a social order largely founded on slavery and the plantation system. These equally dependent institutions produced the essential, especially cotton, from which the South derived its wealth. The North had its own great agricultural resources, was always more advanced commercially, and was also expanding industrially. .
Hostility between the two sections grew clearly after 1820, the year of the Missouri Compromise , which was intended as a permanent solution to the issue in which that hostility was most clearly expressed the question of the extension or prohibition of slavery in the federal territories of the West. .
During the year 1820 through 1821, procedures passed by the U.S. Congress to end the first of a series of crises concerning the extension of slavery. By 1818, Missouri Territory had gained sufficient population to warrant its admission into the Union as a state. Settlers came largely from the South and it was expected that Missouri would be a slave state. To a statehood bill brought before the House of Representatives, James Tallmadge of New York proposed an amendment that would forbid importation of slaves and would bring about the ultimate emancipation of all slaves born in Missouri. This amendment passed the House in February 1819, but not the Senate. The bitterness of the debates sharply emphasized the sectional division of the United States. In January of 1820, a bill to admit Maine as a state passed the House. The admission of Alabama as a slave state in 1819 had brought the slave states and free states to equal representation in the Senate, and it was seen that by pairing Maine and Missouri, this equality would be maintained.