If there is conflict between the stipulations of a treaty and the requirements of a law, the latter must control. A treaty is primarily a contract between two or more independent nations, and is so regarded by writers on public law. For the infraction of its provisions a remedy must be sought by the injured party through reclamations upon the other. When the stipulations are not self-executing they can only be enforced pursuant to legislation to carry them into effect, and such legislation is as much subject to modification and repeal by Congress as legislation upon any other subject. If the treaty contains stipulations which are self-executing, that is, require no legislation to make them operative, to that extent they have the force and effect of a legislative enactment. Congress may modify such provisions, so far as they bind the United States, or supersede them altogether. By the Constitution a treaty is placed on the same footing, and made of like obligation, with an act of legislation. Both are declared by that instrument to be the supreme law of the land, and no superior efficacy is given to either over the other.
Merchants, who imported sugars from San Domingo into the United States, alleged that they should not have had to pay duties on their imported products because the sugars were similar to goods imported from the Hawaiian Islands, which were exempt from duties.
Did the treaty with the Dominican Republic preclude defendant from exacting collections?
The court held that the treaty between the United States and the Dominican Republic did not provide for any concessions of special privileges, which exempted the imported sugar from duties, and the Court affirmed the circuit court's judgment in favor of the collector of the port. The court held that the treaty did not cover concessions like those made to the Hawaiian Islands for a valuable consideration. The treaty imposed an obligation upon both countries to avoid hostile legislation that would discriminate against one country's goods in favor of goods of like character imported from any other country. However, the treaties were not intended to interfere with special arrangements with other countries founded upon a concession of special privileges.