That Congress has no authority to pass laws and bind men's rights beyond the powers conferred by the Constitution, is not open to controversy. But it is insisted that, by the Constitution, Congress has power to legislate for and govern the Territories of the United States, and that by force of the power to govern, laws could be enacted, prohibiting slavery in any portion of the Louisiana Territory; and, of course, to abolish slavery _in all_ parts of it, whilst it was, or is, governed as a Territory. My opinion is, that Congress is vested with power to govern the Territories of the United States by force of the third section of the fourth article of the Constitution. And I will state my reasons for this opinion. Almost every provision in that instrument has a history that must be understood, before the brief and sententious language employed can be comprehended in the relations its authors intended. We must bring before us the state of things presented to the Convention, and in regard to which it acted, when the compound provision was made, declaring: 1st. That "new States may be admitted by the Congress into this Union." 2d. "The Congress shall have power to dispose of and make all needful rules and regulations respecting the territory or other property belonging to the United States. And nothing in this Constitution shall be so construed as to prejudice any claims of the United States, or any particular State." Having ascertained the historical facts giving rise to these provisions, the difficulty of arriving at the true meaning of the language employed will be greatly lessened. The history of these facts is substantially as follows: The King of Great Britain, by his proclamation of 1763, virtually claimed that the country west of the mountains had been conquered from France, and ceded to the Crown of Great Britain by the treaty of Paris of that year, and he says: "We reserve it under our sovereignty, protection, and dominion, for the use of the Indians." This country was conquered from the Crown of Great Britain, and surrendered to the United States by the treaty of peace of 1783. The colonial charters of Virginia, North Carolina, and Georgia, included it. Other States set up pretensions of claim to some portions of the territory north of the Ohio, but they were of no value, as I suppose. (5 Wheat., 375.)