These conferred on their mandatory, Congress, authority to dispose of the territory which belonged to them in common; and to accomplish that object beneficially and effectually, they gave an authority to make suitable rules and regulations respecting it. When the power of disposition is fulfilled, the authority to make rules and regulations terminates, for it attaches only upon territory "belonging to the United States."

Consequently, the power to make rules and regulations, from the nature of the subject, is restricted to such administrative and conservatory acts as are needful for the preservation of the public domain, and its preparation for sale or disposition. The system of land surveys; the reservations for schools, internal improvements, military sites, and public buildings; the pre-emption claims of settlers; the establishment of land offices, and boards of inquiry, to determine the validity of land titles; the modes of entry, and sale, and of conferring titles; the protection of the lands from trespass and waste; the partition of the public domain into municipal subdivisions, having reference to the erection of Territorial Governments and States; and perhaps the selection, under their authority, of suitable laws for the protection of the settlers, until there may be a sufficient number of them to form a self-sustaining municipal Government—these important rules and regulations will sufficiently illustrate the scope and operation of the 3d section of the 4th article of the Constitution. But this clause in the Constitution does not exhaust the powers of Congress within the territorial subdivisions, or over the persons who inhabit them. Congress may exercise there all the powers of Government which belong to them as the Legislature of the United States, of which these Territories make a part. (Loughborough v. Blake, 5 Wheat., 317.) Thus the laws of taxation, for the regulation of foreign, Federal, and Indian commerce, and so for the abolition of the slave trade, for the protection of copyrights and inventions, for the establishment of postal communication and courts of justice, and for the punishment of crimes, are as operative there as within the States. I admit that to mark the bounds for the jurisdiction of the Government of the United States within the Territory, and of its power in respect to persons and things within the municipal subdivisions it has created, is a work of delicacy and difficulty, and, in a great measure, is beyond the cognizance of the judiciary department of that Government. How much municipal power may be exercised by the people of the Territory, before their admission to the Union, the courts of justice cannot decide. This must depend, for the most part, on political considerations, which cannot enter into the determination of a case of law or equity. I do not feel called upon to define the jurisdiction of Congress. It is sufficient for the decision of this case to ascertain whether the residuary sovereignty of the States or people has been invaded by the 8th section of the act of 6th March, 1820, I have cited, in so far as it concerns the capacity and status of persons in the condition and circumstances of the plaintiff and his family.

These States, at the adoption of the Federal Constitution, were organized communities, having distinct systems of municipal law, which, though derived from a common source, and recognising in the main similar principles, yet in some respects had become unlike, and on a particular subject promised to be antagonistic.

Their systems provided protection for life, liberty, and property, among their citizens, and for the determination of the condition and capacity of the persons domiciled within their limits. These institutions, for the most part, were placed beyond the control of the Federal Government. The Constitution allows Congress to coin money, and regulate its value; to regulate foreign and Federal commerce; to secure, for a limited period, to authors and inventors, a property in their writings and discoveries; and to make rules concerning captures in war; and, within the limits of these powers, it has exercised, rightly, to a greater or less extent, the power to determine what shall and what shall not be property.

But the great powers of war and negotiation, finance, postal communication, and commerce, in general, when employed in respect to the property of a citizen, refer to, and depend upon, the municipal laws of the States, to ascertain and determine what is property, and the rights of the owner, and the tenure by which it is held.

Whatever these Constitutions and laws validly determine to be property, it is the duty of the Federal Government, through the domain of jurisdiction merely Federal, to recognise to be property.

And this principle follows from the structure of the respective Governments, State and Federal, and their reciprocal relations. They are different agents and trustees of the people of the several States, appointed with different powers and with distinct purposes, but whose acts, within the scope of their respective jurisdictions, are mutually obligatory. They are respectively the depositories of such powers of legislation as the people were willing to surrender, and their duty is to co-operate within their several jurisdictions to maintain the rights of the same citizens under both Governments unimpaired. A proscription, therefore, of the Constitution and laws of one or more States, determining property, on the part of the Federal Government, by which the stability of its social system may be endangered, is plainly repugnant to the conditions on which the Federal Constitution was adopted, or which that Government was designed to accomplish. Each of the States surrendered its powers of war and negotiation, to raise armies and to support a navy, and all of these powers are sometimes required to preserve a State from disaster and ruin. The Federal Government was constituted to exercise these powers for the preservation of the States, respectively, and to secure to all their citizens the enjoyment of the rights which were not surrendered to the Federal Government. The provident care of the statesmen who projected the Constitution was signalized by such a distribution of the powers of Government as to exclude many of the motives and opportunities for promoting provocations and spreading discord among the States, and for guarding against those partial combinations, so destructive of the community of interest, sentiment, and feeling, which are so essential to the support of the Union. The distinguishing features of their system consist in the exclusion of the Federal Government from the local and internal concerns of, and in the establishment of an independent internal Government within, the States. And it is a significant fact in the history of the United States, that those controversies which have been productive of the greatest animosity, and have occasioned most peril to the peace of the Union, have had their origin in the well-sustained opinion of a minority among the people, that the Federal Government had overstepped its constitutional limits to grant some exclusive privilege, or to disturb the legitimate distribution of property or power among the States or individuals. Nor can a more signal instance of this be found than is furnished by the act before us. No candid or rational man can hesitate to believe, that if the subject of the eighth section of the act of March, 1820, had never been introduced into Congress and made the basis of legislation, no interest common to the Union would have been seriously affected. And, certainly, the creation, within this Union, of large confederacies of unfriendly and frowning States, which has been the tendency, and, to an alarming extent, the result, produced by the agitation arising from it, does not commend it to the patriot or statesman. This court have determined that the intermigration of slaves was not committed to the jurisdiction or control of Congress. Wherever a master is entitled to go within the United States, his slave may accompany him, without any impediment from, or fear of, Congressional legislation or interference. The question then arises, whether Congress, which can exercise no jurisdiction over the relations of master and slave within the limits of the Union, and is bound to recognise and respect the rights and relations that validly exist under the Constitutions and laws of the States, can deny the exercise of those rights, and prohibit the continuance of those relations, within the Territories.

And the citation of State statutes prohibiting the immigration of slaves, and of the decisions of State courts enforcing the forfeiture of the master's title in accordance with their rule, only darkens the discussion. For the question is, have Congress the municipal sovereignty in the Territories which the State Legislatures have derived from the authority of the people, and exercise in the States?

And this depends upon the construction of the article in the Constitution before referred to.

And, in my opinion, that clause confers no power upon Congress to dissolve the relations of the master and slave on the domain of the United States, either within or without any of the States.