It is unnecessary to describe the body of legislation which has been enacted under this grant of power; its variety and extent are well known. But it may be mentioned, in passing, that under this power to regulate commerce, Congress has enacted a great system of municipal laws, and extended it over the vessels and crews of the United States on the high seas and in foreign ports, and even over citizens of the United States resident in China; and has established judicatures, with power to inflict even capital punishment within that country. If, then, this clause does contain a power to legislate respecting the territory, what are the limits of that power? To this I answer, that, in common with all the other legislative powers of Congress, it finds limits in the express prohibitions on Congress not to do certain things; that, in the exercise of the legislative power, Congress cannot pass an ex post facto law or bill of attainder; and so in respect to each of the other prohibitions contained in the Constitution. Besides this, the rules and regulations must be needful. But undoubtedly the question whether a particular rule or regulation be needful, must be finally determined by Congress itself. Whether a law be needful, is a legislative or political, not a judicial, question. Whatever Congress deems needful is so, under the grant of power. Nor am I aware that it has ever been questioned that laws providing for the temporary government of the settlers on the public lands are needful, not only to prepare them for admission to the Union as States, but even to enable the United States to dispose of the lands. Without government and social order, there can be no property; for without law, its ownership, its use, and the power of disposing of it, cease to exist, in the sense in which those words are used and understood in all civilized States. Since, then, this power was manifestly conferred to enable the United States to dispose of its public lands to settlers, and to admit them into the Union as States, when in the judgment of Congress they should be fitted therefor, since these were the needs provided for, since it is confessed that Government is indispensable to provide for those needs, and the power is, to make _all needful_ rules and regulations respecting the territory, I cannot doubt that this is a power to govern the inhabitants of the territory, by such laws as Congress deems needful, until they obtain admission as States. Whether they should be thus governed solely by laws enacted by Congress, or partly by laws enacted by legislative power conferred by Congress, is one of those questions which depend on the judgment of Congress--a question which of these is needful. But it is insisted, that whatever other powers Congress may have respecting the territory of the United States, the subject of negro slavery forms an exception.