Answer:
Well Dred Scott was a slave who had been taken to Wisconsin (free-territory) argued his presence on free soil made him a freeman, then he decided to sue for freedom in 1846 (Missouri). The issue was that congress argued that he did not have the right to sue in federal court, how slaves were property, and how the Missouri comprimise was unconstitutuional.
Explanation:
This is important because Northerners suspected a Democratic conspiracy to settle the slavery question once and for all caused many Northern democrats to vote republican.
