Why was a new case brought to the federal court system? What circumstances made the case a federal question?

The argument Scott used was that because he had lived in a territory where slavery was illegal, he could never again be an enslaved person. He did have reason to believe he would win because this was a doctrine that was recognized in common law for centuries in Europe

Explanation:

are there actual statements because if not my answer would be: that using the five senses the author can create a sense of worth in an object to appeal to the reader and create meaning.