The battle over slavery had threatened to destroy the United States for decades. In the first half of the nineteenth century, the United States was a growing country. Every time a new state was added to the Union, political conflicts erupted over whether the state would be a slave state or a free state. The Fugitive Slave Law of 1850 was actually passed to appease southern senators who were worried when California was admitted to the Union as a free state. But many congressmen were not happy with this compromise and threatened to leave, or secede, from the Union unless the Fugitive Slave Law was strictly enforced.

Hostilities between the North and South continued unabated. It seemed to most Americans that there simply could not be any compromise between those who believed in slavery and those who did not. When antislavery president Abraham Lincoln was...