establishment of a boundary line, which was necessarily left undetermined during the existence of the war. Immediately after the conclusion of the treaty, the American Chargé d'Affaires, by the direction of Mr. Calhoun, who had succeeded Mr. Upshur as Secretary of State, assured the Mexican government, that it was the desire of the President of the United States to settle all questions between the two countries, that might grow out of the treaty, "or any other cause, on the most liberal and satisfactory terms, including that of boundary;" and that the boundary of Texas had been purposely left without specification in the treaty, so that it might be "an open question, to be fairly and fully discussed and settled, according to the rights of each, and the mutual interest and security of the two countries."[1] Shortly after this, an Envoy, (Mr. Shannon,) was sent to Mexico, with full and adequate powers to enter upon the negotiation. He, also, was instructed by Mr. Calhoun, on the 10th of September, 1844, "to renew the declaration made to the Mexican Secretary by our Chargé d'affaires, in announcing the conclusion of the treaty, that the measure was adopted in no spirit of hostility to Mexico, and that, if annexation should be consummated, the United States [would] be prepared to adjust all questions growing out of it, including that of boundary, on the most liberal terms.[2] Assurances of the same purport were made to General Almonte, after the passage of the joint resolutions, by Mr. Buchanan, on the 10th of May, 1845. But Mexico, unmindful of the leniency which had so long been
