Why was the decision in dred Scott v sandford so significant?

The decision in Dred Scott v. Sandford (1857) was significant because it ruled that enslaved African Americans were not U.S. citizens and therefore had no standing to sue in federal court. Additionally, the Supreme Court declared the Missouri Compromise unconstitutional, effectively allowing slavery to expand into the western territories. This ruling intensified national tensions over slavery, contributed to the rise of the abolitionist movement, and is often cited as a catalyst for the Civil War.