Let us suppose the whole of Mexico conquered by our arms, it may be divided, in the first instance, into four or five territories, which may be retained in that form of government at least as long as Florida, and be, afterwards, admitted as States, or be permitted to establish independent governments, bound to us by treaties of alliance, offensive and defensive. I hold it as a settled principle, that we cannot hold conquered countries like ancient or modern nations; and we cannot, without violating the spirit of our institutions, deny them the right of self-government, or at least, of representation. The conquests we may make, cannot fail to better the condition of the conquered, by affording them better political institutions than those they before possessed. Surely, nothing can be worse than the present military anarchy of Mexico. They would obtain security for their rights, and obtain new ones, which they never enjoyed before; they would have peace within their borders, and safety from without. We should repel with indignation, the terms of reproach heaped upon us by the “tory” paper of England, the “Times.” Our free governments carry blessings with them wherever they appear. Plunder and devastation, form no part of the American character, as is proved by the progress of our arms, marked by a degree of humanity unexampled in the annals of war and conquest. The affectation of concern for their religion, manifested by the Mexicans, is truly ridiculous in those who tolerate no religion but that of the State. The subject of slavery is one of local, that is, of State or territorial legislation, except as to the foreign slave trade, which belongs to Congress in the regulation of foreign commerce. In the territory Northwest of the Ohio, there could not be said to be any system of law, it being uninhabited, or at least, the population was so inconsiderable, that it was not taken into consideration in establishing the ordinance of 1787, before the adoption of the present Constitution. It is in the nature of a compact between the States, and is not a case in point. But in Louisiana, the institution of slavery was already there, and could not be destroyed without interfering with a subject of local regulation of those territories, together with other subjects of domestic concern. Congress reserved to itself only a right to repeal, resembling a veto, except that the laws enacted continued in force until repealed; but, in no instance did Congress take the initiative in this local legislation. We may often discover the best expositions of the power of the Government, or any branch of it, by strict enquiry into the history of its practical operation.