American Civil War (1861-1865) was a civil war between the United states (the Union) and the Southern slave states of the newly formed Confederate States of America under Jefferson Davis. The Union included all the free states and the five slave holding Border States. Abraham Lincoln and the Republican army led the union. The Republicans opposed the expansion of slavery into territories owned by the United States and their victory in the presidential election of 1860 resulted in seven southern states declaring their succession from the union even before Lincoln took office. The Union rejected succession and regarded it as a rebellion. This conflict initiated the American Civil War that threatened the unity and integrity of newly formed United States. The victory in the war ended slavery in the United States and restored the union by settling the issue of nullification and succession and strengthened the role of the federal government. The social, political, economic and racial issues of the war continue to impact contemporary American thought.
The main explanation for the origins of the American Civil War was slavery and its expansion into the territories. States’ rights and the tariff issue became entangled in the slavery issue and were intensified by it. Other important factors party politics, expansionism, sectionalism etc. The United States was a nation divided into two distinct regions separated by the Mason – Dixon line. New England, the northeast and the Midwest had a rapidly growing economy based on family farms, industry, mining, commerce and transportation with a rapidly growing urban population and no slavery outside the Border States. A high birth rate and huge number of European immigrants fed its growth. The south was dominated by a settled plantation system based on slavery with rapid growth taking place in the southwest such as Texas based on high birth rates and low immigration from Europe. There were few cities or towns and little manufacturing units. Slave owners controlled politics and economy of the region. Overall the northern population was growing much more quickly than the southern population that made it increasingly difficult for the south to continue to control the national government. Southerners were worried about the relative political decline of their region because the north was growing much faster in terms of population and industrial output. In the interest of maintaining unity politicians opposed slavery moderately resulting in numerous compromise such as Missouri Compromise of 1820.After the Mexican American war the issue of slavery in the new territories led to the Compromise of 1850.While the compromise averted an immediate political crisis it did not permanently resolve the issue of the Slave power. Amid the emergence of increasingly hostile sectional ideologies in national politics the collapse of the old second party system in the 1850s hampered efforts of the politicians to reach yet one more compromise. The compromise that was reached (the Kansas- Nebraska Act) outraged the northerners. In the 1850s with the rise of the Republican party the first major party with no appeal in the south the industrializing North and agrarian mid west became committed to the economic ethos of free –labor industrial capitalism. After 1840 abolitionists denounced slavery as more than a social evil. Many northerners especially leaders of the new Republican party considered slavery a great national evil and believed that a small number of southern owners of large plantations controlled the national government with the goal of spreading that evil. In 1860 the election of Abraham Lincoln who won the national election without receiving a single electoral vote from any of the southern states triggered the secession of the southern states from the union and their formation of the Confederate State of America.