1.
When the abolitionist John Brown seized the largest Federal arsenal at Harpers Ferry, Virginia, in October of 1859, he forced the citizens of the United States to reconsider the immorality of the institution of slavery and the injustices enforced by the government. The raid on Harpers Ferry and the resulting execution of Brown was a major turning point in the American abolitionist movement, causing many peaceful abolitionists to accept more militant measures to push for the end of slavery. The legitimization of slavery by the state and societal violence, such as the “Bleeding Kansas” conflict, plagued a nation rapidly approaching civil war, and during the 1850s, the U.S. faced extreme sectional tension as slave-holding and free states struggled to maintain a balance of power in a divided government. Brown’s actions were a reflection of the violence of his time and a reaction to what he viewed as the legalized criminality of slavery upheld by the state under which he lived. Brown’s actions in Virginia and at the battle of Osawatomie, Kansas, were applauded by the antislavery populace, and New England abolitionists and intellectuals, such as Henry David Thoreau and Ralph Waldo Emerson, unaware of the bloody details of Brown’s operations at the Pottawatomie Massacre in Kansas, helped to establish the image of Brown as a martyr in the North. Henry David Thoreau and Ralph Waldo Emerson championed John Brown’s sacrifice while overlooking the violent aspects of Brown’s character, in order to promote him as a heroic symbol for the abolitionist cause. As a result of this judgment by New England intellectuals and the ensuing martyrdom of Brown in the North, many Southerners viewed the raid as a larger Northern scheme to directly attack the South, leading to increased sectional distrust and accelerating the approach of secession in 1861. Â
The secession of the Southern states and the firing on Ft. Sumter on April 12, 1861, ended a long period of unsuccessful compromises that failed to maintain national unity. During the first half of the nineteenth century, the young nation struggled to preserve a political equilibrium between slave and free states as new territories in the west began to enter into statehood. In 1820 the federal government issued the Missouri Compromise to establish a balance between incoming slave and free states. Although half of the U.S. was composed of slave-holding states, Northern free states benefited from the institution of slavery. Major cities, such as New York City and Boston, grew rich from the textile industry, which heavily depended on the supply of cotton picked by American slaves. Ironically, the slavery-dependent textile industry increased the wealth of the city of Boston during the 1800s, allowing it to become a center of American art and culture, from which the abolitionist movement would emerge. Abolitionists demanded the emancipation of slaves in Washington DC and many began to demand the immediate abolition of slavery in the U.S., protesting the government’s legitimization of the slavery system. An increased number of antislavery petitions were sent to Congress but were blocked from consideration by the effect of the Gag Rule in the House of Representatives that had been put into place in 1836. To assuage the growing political tension between slaveholders and Free-Soilers, the federal government enacted the Compromise of 1850, which included the controversial Fugitive Slave Act, requiring free state officials to return runaway slaves to their masters, and in 1854 Congress passed the Kansas-Nebraska Act, allowing local citizens to decide whether slavery should be allowed in the Kansas and Nebraska territories through Popular Sovereignty. The U.S. government, constricted by the contrasting interests between slaveholders, Free-Soilers, and the more radical demands of the increasingly popular abolitionists, began to face extreme sectional disharmony, which was reflected in the escalation of violence in American society.
2.
The U.S. Supreme Court's ruling in the Dred Scott case struck down the  issouri Compromise as unconstitutional, maintaining that Congress had no power to forbid or abolish slavery in the territories
