Why did Dred Scott feel he should be a free man?

Dred Scott believed he should be a free man because he had lived in free territories where slavery was prohibited, specifically Illinois and Wisconsin, with his owner. He argued that his residence in these free areas gave him the right to claim his freedom. Additionally, Scott contended that since he was a person and not merely property, he should be entitled to legal rights and protections under the law. His case ultimately led to the landmark Supreme Court decision in 1857, which denied his claim and stated that African Americans could not be considered citizens.