On meeting the commissioners, Mr. Trist exhibited his powers, which were ample, but that of the Mexicans was simply confined to hearing propositions from Mr. Trist. Mr. Trist objected to this limitation, but was assured that when it became necessary to sign the treaty they would exhibit full powers. The American commissioners presented the project of a treaty the leading feature of which related to the boundary line between the two countries. It was also a part of the project that Mexico was to concede to the United States the right of transport across the Isthmus of Tehuantepec free from tolls. These and all else asked by Mr. Trist were refused. The Mexican commissioners asked for further instructions from their Government, which were given—that they should neither exceed nor modify the former instructions given them. They asked to be relieved, as these instructions placed them in an embarrassing position. A council of ministers was called, and their former instructions were changed so as to authorize them "to approximate to them as much as possible, agreeing to some modifications which the circumstances of the country may exact, as well as to things of minor importance which may arise during the discussion."
On September 1st, when the third meeting was held, the Mexican commissioners exhibited plenary powers. No agreement being reached, it was proposed to extend the armistice for forty-five days. But on September 5th the Mexican commissioners were informed that the Government would not consent to the extension or to the cession of New Mexico, which Mr. Trist had insisted on. The Mexican commissioners then submitted a counter project on the 6th, which in effect refused all of the more important concessions asked by the United States. With this the diplomatic conferences terminated. General Scott at once called a conference with his general officers. He stated to them the bad faith of the enemy, who commenced the work of repair on their fortifications. He recited the incident of the mobbing of teamsters. He closed by saying: "I have therefore called you to headquarters to advise upon the propriety of dissolving the armistice, or [after a pause] to inform you that I have dissolved it, and to read to you my letter to General Santa Anna notifying him of the fact." Looking for the letter, he said, "I have torn it up." He at once wrote a note and dispatched it to General Santa Anna, as follows:
"Headquarters, Army of the United States of America,
"Tacubaya, September 6, 1847.
"To his Excellency the President and General in Chief of the Mexican Republic.
"Sir: The seventh article, as also the twelfth, that stipulates that trade shall remain unmolested—of the armistice or military convention which I had the honor to ratify and to exchange with your Excellency the 24th ultimo—has been repeatedly violated, beginning soon after date, on the part of Mexico; and I now have good reasons to believe that within the last forty-eight hours, if not earlier, the third article of that convention has been equally violated by the same party. These direct breaches of faith give to this army the most perfect right to resume hostilities against Mexico, without any notice whatever; but, to allow time for possible apology or reparation, I now give formal notice that, unless full satisfaction on these allegations should be received by me by 12 o'clock meridian to-morrow, I shall consider the said armistice at an end from and after that hour.
"I have the honor to be your Excellency's most obedient servant,
"Winfield Scott."
General Santa Anna replied in an insolent note, denying General Scott's charges and making counter charges.
Many newspapers throughout the United States criticised General Scott in the severest terms for being duped by General Santa Anna into an armistice which the latter only desired to recruit his army. There is the strongest evidence—that of Mr. Trist and the Mexican commissioners—that Santa Anna was really desirous to make peace. The manifesto which he issued to the nation is itself sufficient proof on this score; and certainly it reflects the highest credit on General Scott, that when he was at the very gates of the capital, which he could have entered in a few hours, he was willing to spare not only the lives of his own gallant army, but those of the enemy. Santa Anna now called a meeting of the principal officers and governmental civilians to meet him in the palace, and it was agreed to continue resistance.