It has been supposed, in the argument on the part of the plaintiff, that the eighth section of the act of Congress passed March 6, 1820, (3 St. at Large, p. 544,) which prohibited slavery north of thirty-six degrees thirty minutes, within which the plaintiff and his wife temporarily resided at Fort Snelling, possessed some superior virtue and effect, extra-territorially, and within the State of Missouri, beyond that of the laws of Illinois, or those of Ohio in the case of Strader et al. _v._ Graham. A similar ground was taken and urged upon the court in the case just mentioned, under the ordinance of 1787, which was enacted during the time of the Confederation, and re-enacted by Congress after the adoption of the Constitution, with some amendments adapting it to the new Government. (1 St. at Large, p. 50.) In answer to this ground, the Chief Justice, in delivering the opinion of the court, observed: "The argument assumes that the six articles which that ordinance declares to be perpetual, are still in force in the States since formed within the territory, and admitted into the Union. If this proposition could be maintained, it would not alter the question; for the regulations of Congress, under the old Confederation or the present Constitution, for the government of a particular Territory, could have no force beyond its limits. It certainly could not restrict the power of the States, within their respective territories, nor in any manner interfere with their laws and institutions, nor give this court control over them. "The ordinance in question, he observes, if still in force, could have no more operation than the laws of Ohio in the State of Kentucky, and could not influence the decision upon the rights of the master or the slaves in that State." This view, thus authoritatively declared, furnishes a conclusive answer to the distinction attempted to be set up between the extra-territorial effect of a State law and the act of Congress in question. It must be admitted that Congress possesses no power to regulate or abolish slavery within the States; and that, if this act had attempted any such legislation, it would have been a nullity. And yet the argument here, if there be any force in it, leads to the result, that effect may be given to such legislation; for it is only by giving the act of Congress operation within the State of Missouri, that it can have any effect upon the question between the parties. Having no such effect directly, it will be difficult to maintain, upon any consistent reasoning, that it can be made to operate indirectly upon the subject.