But there is another point in the case which depends on State power and State law. And it is contended, on the part of the plaintiff, that he is made free by being taken to Rock Island, in the State of Illinois, independently of his residence in the territory of the United States; and being so made free, he was not again reduced to a state of slavery by being brought back to Missouri. Our notice of this part of the case will be very brief; for the principle on which it depends was decided in this court, upon much consideration, in the case of Strader et al. _v._ Graham, reported in 10th Howard, 82. In that case, the slaves had been taken from Kentucky to Ohio, with the consent of the owner, and afterwards brought back to Kentucky. And this court held that their _status_ or condition, as free or slave, depended upon the laws of Kentucky, when they were brought back into that State, and not of Ohio; and that this court had no jurisdiction to revise the judgment of a State court upon its own laws. This was the point directly before the court, and the decision that this court had not jurisdiction turned upon it, as will be seen by the report of the case. So in this case. As Scott was a slave when taken into the State of Illinois by his owner, and was there held as such, and brought back in that character, his _status_, as free or slave, depended on the laws of Missouri, and not of Illinois. It has, however, been urged in the argument, that by the laws of Missouri he was free on his return, and that this case, therefore, cannot be governed by the case of Strader et al. _v._ Graham, where it appeared, by the laws of Kentucky, that the plaintiffs continued to be slaves on their return from Ohio. But whatever doubts or opinions may, at one time, have been entertained upon this subject, we are satisfied, upon a careful examination of all the cases decided in the State courts of Missouri referred to, that it is now firmly settled by the decisions of the highest court in the State, that Scott and his family upon their return were not free, but were, by the laws of Missouri, the property of the defendant; and that the Circuit Court of the United States had no jurisdiction, when, by the laws of the State, the plaintiff was a slave, and not a citizen.