When once made, they are obligatory on our side as laws, and can be abrogated by no power less than that which may abrogate existing laws.

Not the President alone, not the President and Senate, can set them aside; but for this purpose the whole power of the Government must be invoked, in its most solemn form, by Act of Congress.

In conformity with this requirement, the power to declare war, involving, of course, the abrogation of treaties, is expressly lodged with Congress.

It is therefore indispensable that they should have the obligation and force of a law, that they may be executed by the judicial power, and be obeyed like other laws.

A treaty is in its nature a contract between two nations, not a legislative act.… In the United States a different principle is established.

Our Constitution declares a treaty to be the law of the land.

Justice Iredell, of North Carolina, passed directly upon the power of Congress, asserting that to this body alone was given the power to abrogate a treaty under our Constitution.

It is a part of the Law of Nations, that, if a treaty be violated by one party, it is at the option of the other party, if innocent, to declare, in consequence of the breach, that the treaty is void.

Never before has the President assumed to act without the House of Representatives in the performance of this duty.

This very Act of Congress originated in the Senate, which at that day undertook to exercise no such power as is now claimed.

Such, Sir, is the rule of the Constitution, sustained by authoritative precedents, in the abrogation of successive treaties with two powerful nations, France and Great Britain.

Surely there cannot be one rule for large nations and another for small nations; nor will any one argue that a treaty with France or Great Britain can be abrogated only by Act of Congress, but a treaty with Denmark may be abrogated by the…

Not content with the treaty-making power which it possesses under the Constitution, it assumes the treaty-abrogating power, which it does not possess.

And this assumption becomes more objectionable, when it is considered how completely it excludes the House of Representatives from an important function in the Government.

Louis the Fourteenth, in the pride of conscious power, exclaimed, “I am the State”; and permit me to say, that our own Executive, undertaking to act in this matter without the sanction of Congress, effectively makes the same declaration.

Only lately it authorized the origination of the great appropriation bills, constituting the mainspring of the Government, in defiance of uninterrupted usage, and, as I submit, the spirit of the Constitution.

Whatever may be the merits of the existing controversy with Denmark, I trust that the President will not clutch so eagerly at the promised fruits as to disregard the requirement of the Constitution, and the voice of the popular branch, in…

To do even a great right, it is not safe to do even a little wrong.

The treaty with Denmark is at this moment part of the supreme law of the land, and can be abrogated only by Act of Congress.

We must look for our rule of conduct to our own Constitution.

The President, by and with the advice and consent of the Senate, may make treaties; but there is nothing in our Constitution conferring upon them the power to abrogate treaties.

To attribute to them any such power is to go beyond the Constitution.

On the contrary, I think that Senators on the other side--both the Senator from Virginia and the Senator from Connecticut--admit that a treaty cannot be abrogated, except by virtue of an Act of Congress.

And I come back again to the admission of both Senators, that a treaty can be abrogated only by Act of Congress.

Let us at all hazards prevent the extension of Slavery and the increase of the Slave Power.