How did the dred Scott decision of 1857 increase sectionalism in the US?

The Dred Scott decision of 1857 heightened sectionalism by ruling that African Americans could not be citizens and that Congress lacked the authority to prohibit slavery in the territories. This angered abolitionists in the North, who viewed the ruling as a betrayal of democratic principles, while it emboldened pro-slavery advocates in the South. The ruling intensified the existing divide between free and slave states, contributing to the growing tensions that ultimately led to the Civil War. It exemplified the deep-seated conflicts over slavery and states' rights, further polarizing the nation.