tes which shall be made in pursuance
thereof, and all treaties made or which shall be made under the
authority of the United States, shall be the supreme law of the land."
This has made treaties part of our municipal law; but it has not
assigned to them any particular degree of authority, nor declared that
laws so enacted shall be irrepealable. No supremacy is assigned to
treaties over acts of Congress. That they are not perpetual, and must
be in some way repealable, all will agree.

If the President and the Senate alone possess the power to repeal or
modify a law found in a treaty, inasmuch as they can change or
abrogate one treaty only by making another inconsistent with the
first, the Government of the United States could not act at all, to
that effect, without the consent of some foreign Government. I do not
consider, I am not aware it has ever been considered, that the
Constitution has placed our country in this helpless condition. The
action of Congress in repealing the treaties with France by the act of
July 7th, 1798, (1 Stat. at Large, 578,) was in conformity with these
views. In the case of Taylor et al. _v._ Morton, (2 Curtis's Cir. Ct.
R., 454,) I had occasion to consider this subject, and I adhere to
the views there expressed.

If, therefore, it were admitted that the treaty between the United
States and France did contain an express stipulation that the United
States would not exclude slavery from so much of the ceded territory
as is now in question, this court could not declare that an act of
Congress excluding it was void by force of the treaty. Whether or no a
case existed sufficient to justify a refusal to execute such a
stipulation, would not be a judicial, but a political and legislative
question, wholly beyond the authority of this court to try and
determine. It would belong to diplomacy and legislation, and not to
the administration of existing laws. Such a stipulation in a treaty,
to legislate or not to legislate in a particular way, has been
repeatedly held in this court to address itself to the political or
the legislative power, by whose action thereon this court is bound.
(Foster _v._ Nicolson, 2 Peters, 314; Garcia _v._ Lee, 12 Peters,
519.)

But, in my judgment, this treaty contains no stipulation in any manner
affecting the action of the United States respecting the territory in
question. Before examining the language of the treaty, it is material
to bear in mind that the part of the ce