Final answer:
The Supreme Court case that most contributed to the start of the Civil War was Dred Scott v. Sanford.
Step-by-step explanation:
The Supreme Court case that most clearly contributed to the start of the Civil War was Dred Scott v. Sanford. In this case, the Supreme Court ruled that enslaved individuals were not considered citizens and therefore did not have the right to sue for their freedom. This decision further deepened the divide between the North and the South on the issue of slavery, ultimately leading to the outbreak of the Civil War.
Learn more about Supreme Court case contributing to the start of the Civil War