The Civil War between the North and South had several major causes. The obvious cause to most casual historic observers was the debate over the continuation of slavery. The Mason-Dixon Line and the Missouri Compromise were both intended to define the boundaries of slavery, and did so in a geographic sense. But the ideas and practices upon which slavery was founded were controversial on both sides and strong opinions made people ready and willing to take strong actions.
Beyond the debate about slavery, however, there were basic conflicts about lifestyle and values of society between the two parts of the nation. The South was much more dependent upon agriculture and family enterprise for its economy; the North had more industrial development, more business, and more varied natural resources. Disagreements over how the benefits of these differing economic conditions might be shared with the other areas of the nation also entered into the underlying beliefs feeding the development of the Civil War.
The Civil War had several causes – sectionalism, the extension of slavery into new territories, and states’ rights. The 1800's saw a growth in regional differences among Americans. The North, South, and West had developed their own unique economy and culture. It was ideal of self-preservation of their way of life that ultimately led to the conflict.
The Nullification crisis grew from several states desire to strengthen the federal government. It was argued that states should have a right to reject of nullify a federal law if it disagreed with that law. The idea arose regarding the tariff issues of 1828 which increased duties on raw materials while lowering the tariff on manufactured textiles. This was very displeasing to the South who thought the tariffs were too high which would cause European nations to retaliate against importation of U.S. crops.
Slavery divided the nation as the prospect of slavery in the new territories threatened balance between slave and free states. All the compromises failed. The Confederate States of America was established when Lincoln was elected out of fear as President he would outlaw slavery.