Hamilton Fish to James F. Wilson, May 17, 1872

Mr. Fish to Mr. Wilson.

Sir: Your dispatches numbers 85 and 86, dated, respectively, the 7th and 10th ultimo, have been received. In these dispatches you inform the Department that General Palacios, then in command of the military forces of the republic of Mexico, stationed at the city of Matamoras, had, on the 8th of that month, issued a proclamamation, the eighth article of which provides that the approach to the place of any vessel is prohibited, be it a war or merchant vessel, large or small, Mexican or foreign, either ascending or descending the Bravo (Rio Grande) within a visual radius of four leagues, measured from the piriometer of the fortification adjacent to the Bravo, at both extremes, unless a special permit shall have been previously given by this office, (comandancia), with previous knowledge of some agent or officer of the nation concerned.” In the same connection you have forwarded copy of a note of General Palacios to you, in reply to a communication which you had previously addressed to him asking for an explanation of his proclamation, and especially of the eighth article.

In his note to you, General Palacios says, “that the prohibition contained in this article is a precautionary military measure, which will only be enforced when the enemy presents himself at the port of the place, and that not the least intention exists to molest American commerce; that by reason of the necessity of a just and legitimate defense, the article in question embraces American vessels; that the spirit of the article is to exercise surveillance, within the radius therein mentioned, over all vessels, if there is good reason to suspect their hostility to the place visited; that if a search shall show all suspicion to have been unfounded the vessel shall be allowed to proceed, and if it shall appear that the suspicion was well-founded, she shall not be allowed to enter the prohibited port; and that, according to the character of the objects found on board, information will be sent to the agent or officer representing the nation to which such vessel belongs of the permit granted or refused, before or after the departure of such vessel.”

While accepting the statements of General Palacios’s note, as to the true intent and meaning of the proclamation, and also in relation to the friendly disposition of the Mexican government toward the vessels and commerce of the United States, it is nevertheless clear that the eighth article of the proclamation of General Palacios is in contravention of the provisions of the treaty of February, 1848, between the United States and Mexico. The river Bravo, or Rio Grande, is a common boundary between the United States and Mexico; it is a navigable river, and, according to universally accepted principles of public law, must be recognized as a common highway for the commerce of both nations. The seventh article of the treaty of February, 1848, recognizing the principle just stated, provides that “the navigation of the Gila and of the Rio Bravo, below said boundary, (southern boundary of New Mexico,) shall be free and common to the vessels and citizens of both countries, and neither shall without the consent of the other construct any work that may impede in whole or in part the exercise of this right.”

Vessels of the United States navigating the Rio Grande, whether ascending or descending, are liable to be subjected to the surveillance of the proposed regulations, and this regardless of the fact of whether such vessels are destined to or intending to touch at any port on the Mexican side of the river. That the exercise of such surveillance upon vessels belonging to the United States, by the authorities of Mexico, would be an impediment to the exercise of the right of the free navigation of the river by such vessels, it needs no argument to maintain. The government of Mexico may prohibit vessels navigating the Rio Grande from entering the ports or landing on the shore of the river, within the territory of that republic, or it may attach such conditions to the entering or landing of such vessels within the territories of Mexico as circumstances shall in the judgment of that government demand, but such regulations cannot properly be extended so as in any manner to impede the exercise of the right of free navigation of the river by vessels belonging to the United States. The correctness of this view of the force of the article in question must be, it is believed, at once apparent to General Palacios.

You will, therefore, on receipt of this instruction, avail yourself of the earliest opportunity to bring the matter to the attention of General Palacios, and assure him that this Department will learn with satisfaction that the regulations and surveillance proposed by the eighth article of his proclamation is no longer sought to be enforced against vessels belonging to the United States navigating the river Rio Grande.

I am, sir, your obedient servant,