The sequence of events leading up to the Civil War started with the growing conflict between the Northern states and the Southern states. The four main causes of the conflicts between the North and the South were: slavery, Constitutional disputes, economical differences and political blunders and extremism. Northern historians argue the cause of the Southern states leaving the Union was because of the South's strong attachment to slavery, while Southern historians view that the conflict between the two sections were chiefly due to their outlook of the U.S Constitution. The three important reasons that caused the breakup of the Union were the passing of the Kansas-Nebraska Act, the monumental decision of the Dred Scott case and the on-going debate of slavery. Senator Stephen A. Douglass devised a bill that would anger the Northerners and draw a wedge between the North and the South. .
This bill was known as the Kansas-Nebraska Act (1854). This suggested that the Nebraska territory be divided into two sections: Kansas and Nebraska. The settlers who settled in these territories would be able to decide (popular sovereignty) whether to not to keep slavery or to make it a free state. Since these territories were located North of the 36 30' line, this would be a tremendous opportunity for the Southern farmers that they did not receive in the Missouri Compromise. The bill was passed and the sectional controversy only grew. Stephen Douglass came to the defense of the Kansas-Nebraska Act saying, " the bill does equal and exact justice to the whole Union, and every part of it and leave the people thereof to the free enjoyment of all their rights."" Northern democrats saw this Act as a way of spreading slavery. Congressional stupidity and presidential incompetence also contributed to the crisis of the 1850's. The Supreme Court enraged the North with its controversial proslavery decision of the Dred Scott case.