engagements, and have no moral power to break them. Treaties between
nations repose on this principle. If the new State can revoke and annul
an article concluded between itself and the United States, by which
slavery is excluded from it, it may revoke and annul any other article
of the compact; it may, for example, annul the article respecting public
lands, and in virtue of its sovereignty, assume the right to tax and to
sell the lands of the United States. There is yet a more satisfactory
answer to this objection. The judicial power of the United States is
co-extensive with their legislative power, and every question arising
under the Constitution or laws of the United States, is recognizable by
the judiciary thereof. Should the new State rescind any of the articles
of compact contained in the act of admission into the Union, that, for
example, by which slavery is excluded, and should pass a law authorizing
slavery, the judiciary of the United States on proper application, would
immediately deliver from bondage, any person retained as a slave in said
State. And, in like manner, in all instances affecting individuals,
the judiciary might be employed to defeat every attempt to violate the
Constitution and laws of the United States.

If Congress possess the power to exclude slavery from Missouri, it still
remains to be shown that they ought to do so. The examination of this
branch of the subject, for obvious reasons, is attended with peculiar
difficulty, and cannot be made without passing over arguments which, to
some of us, might appear to be decisive, but the use of which, in this
place, would call up feelings, the influence of which would disturb, if
not defeat, the impartial consideration of the subject.

Slavery, unhappily, exists within the United States. Enlightened men, in
the States where it is permitted, and everywhere out of them, regret its
existence among us, and seek for the means of limiting and of mitigating