The letters of Mr. Trist to the Secretary of State, and especially such of them as bear date subsequent to the receipt by him of his letter of recall as commissioner, it will be perceived, contain much matter that is impertinent, irrelevant, and highly exceptionable.  Four of these letters, bearing date, respectively, the 29th December, 1847, January 12, January 22, and January 25, 1848, have been received since the treaty was submitted to the Senate.  In the latter it is stated that the Mexican commissioners who signed the treaty derived “their full powers, bearing date on the 30th December, 1847, from the President ad interim of the Republic (General Anaya), constitutionally elected to that office in November by the Sovereign Constituent Congress” of Mexico.  It is impossible that I can approve the conduct of Mr. Trist in disobeying the positive orders of his Government contained in the letter recalling him, or do otherwise than condemn much of the matter with which he has chosen to encumber his voluminous correspondence.  Though all of his acts since his recall might have been disavowed by his Government, yet Mexico can take no such exception.  The treaty which the Mexican commissioners have negotiated with him, with a full knowledge on their part that he had been recalled from his mission, is binding on Mexico.

Looking at the actual condition of Mexico, and believing that if the present treaty be rejected the war will probably be continued at great expense of life and treasure for an indefinite period, and considering that the terms, with the exceptions mentioned in my message of the 22d instant, conform substantially, so far as relates to the main question of boundary, to those authorized by me in April last, I considered it to be my solemn duty to the country, uninfluenced by the exceptionable conduct of Mr. Trist, to submit the treaty to the Senate with a recommendation that it be ratified, with the modifications suggested.

Nothing contained in the letters received from Mr. Trist since it was submitted to the Senate has changed my opinion on the subject.

The resolution also calls for “all the correspondence between General Scott and the Government since the arrival of Mr. Trist in Mexico.”  A portion of that correspondence, relating to Mr. Trist and his mission, accompanies this communication.  The remainder of the “correspondence between General Scott and the Government” relates mainly, if not exclusively, to military operations.  A part of it was communicated to Congress with my annual message, and the whole of it will be sent to the Senate if it shall be desired by that body.  As coming within the purview of the resolution, I also communicate copies of the letters of the Secretary of War to Major-General Butler in reference to Mr. Trist’s remaining at the headquarters of the Army in the assumed exercise of his powers of commissioner.

JAMES K. POLK.

WASHINGTON, March 2, 1848.