. 580, 598-599
(1884). The repealability of treaties by act of Congress was first
asserted in an opinion of the Attorney General in 1854 (6 Op. Atty. Gen.
291). The year following the doctrine was adopted judicially in a
lengthy and cogently argued opinion of Justice Curtis, speaking for a
United States circuit court in Taylor _v._ Morton, 23 Fed. Cas. No.
13,799 (1855). The case turned on the following question: "If an act of
Congress should levy a duty upon imports, which an existing commercial
treaty declares shall not be levied, so that the treaty is in conflict
with the act, does the former or the latter give the rule of decision in
a judicial tribunal of the United States, in a case to which one rule or
the other must be applied?"

Citing the supremacy clause of the Constitution, Justice Curtis said:
"There is nothing in the language of this clause which enables us to
say, that in the case supposed, the treaty, and not the act of Congress,
is to afford the rule. Ordinarily, treaties are not rules prescribed by
sovereigns for the conduct of their subjects, but contracts, by which
they agree to regulate their own conduct. This provision of our
Constitution has made treaties part of our municipal law. But it has not
assigned to them any particular degree of authority in our municipal
law, nor declared whether laws so enacted shall or shall not be
paramount to laws otherwise enacted. * * * [This] is solely a question
of municipal, as distinguished from public law. The foreign sovereign
between whom and the United States a treaty has been made, has a right
to expect and require its stipulations to be kept with scrupulous good
faith; but through what internal arrangements this shall be done, is,
exclusively, for the consideration of the United States. Whether the
treaty shall itself be the rule of action of the people as well as the
government, whether the power to enforce and apply it shall reside in
one department, or another, neither the treaty itself, nor any
implication drawn from it, gives him any right to inquire. If the people
of the United States were to repeal so much of their constitution as
makes treaties part of their municipal law, no foreign sovereign with
whom a treaty exists could justly complain, for it is not a matter with
which he has any concern. * * * By the eighth section of the first
article of the Constitution, power is conferred on Congress to regulate
commerce with foreign nations, and to lay