It was deemed proper to issue this order, because soon after the President of Texas, in April, 1845, had issued his proclamation convening the Congress of that Republic for the purpose of submitting to that body the terms of annexation proposed by the United States the Government of Mexico made serious threats of invading the Texan territory. These threats became more imposing as it became more apparent in the progress of the question that the people of Texas would decide in favor of accepting the terms of annexation, and finally they had assumed such a formidable character as induced both the Congress and convention of Texas to request that a military force should be sent by the United States into her territory for the purpose of protecting and defending her against the threatened invasion. It would have been a violation of good faith toward the people of Texas to have refused to afford the aid which they desired against a threatened invasion to which they had been exposed by their free determination to annex themselves to our Union in compliance with the overture made to them by the joint resolution of our Congress. Accordingly, a portion of the Army was ordered to advance into Texas. Corpus Christi was the position selected by General Taylor. He encamped at that place in August, 1845, and the Army remained in that position until the 11th of March, 1846, when it moved westward, and on the 28th of that month reached the east bank of the Rio Grande opposite to Matamoras. This movement was made in pursuance of orders from the War Department, issued on the 13th of January, 1846. Before these orders were issued the dispatch of our minister in Mexico transmitting the decision of the council of government of Mexico advising that he should not be received, and also the dispatch of our consul residing in the City of Mexico, the former bearing date on the 17th and the latter on the 18th of December, 1845, copies of both of which accompanied my message to Congress of the 11th of May last, were received at the Department of State. These communications rendered it highly probable, if not absolutely certain, that our minister would not be received by the Government of General Herrera. It was also well known that but little hope could be entertained of a different result from General Paredes in case the revolutionary movement which he was prosecuting should prove successful, as was highly probable. The partisans of Paredes, as our minister in the dispatch referred to states, breathed the fiercest hostility against the United States, denounced the proposed negotiation as treason, and openly called upon the troops and the people to put down the Government of Herrera by force. The reconquest of Texas and war with the United States were openly threatened. These were the circumstances existing when it was deemed proper to order the Army under the command of General Taylor to advance to the western frontier of Texas and occupy a position on or near the Rio Grande.
The apprehensions of a contemplated Mexican invasion have been since fully justified by the event. The determination of Mexico to rush into hostilities with the United States was afterwards manifested from the whole tenor of the note of the Mexican minister of foreign affairs to our minister bearing date on the 12th of March, 1846. Paredes had then revolutionized the Government, and his minister, after referring to the resolution for the annexation of Texas which had been adopted by our Congress in March, 1845, proceeds to declare that—
A fact such as this, or, to speak with greater exactness, so notable an act of usurpation, created an imperious necessity that Mexico, for her own honor, should repel it with proper firmness and dignity. The supreme Government had beforehand declared that it would look upon such an act as a casus belli, and as a consequence of this declaration negotiation was by its very nature at an end, and war was the only recourse of the Mexican Government.
It appears also that on the 4th of April following General Paredes, through his minister of war, issued orders to the Mexican general in command on the Texan frontier to "attack" our Army "by every means which war permits." To this General Paredes had been pledged to the army and people of Mexico during the military revolution which had brought him into power. On the 18th of April, 1846, General Paredes addressed a letter to the commander on that frontier in which he stated to him: "At the present date I suppose you, at the head of that valiant army, either fighting already or preparing for the operations of a campaign;" and, "Supposing you already on the theater of operations and with all the forces assembled, it is indispensable that hostilities be commenced, yourself taking the initiative against the enemy."
The movement of our Army to the Rio Grande was made by the commanding general under positive orders to abstain from all aggressive acts toward Mexico or Mexican citizens, and to regard the relations between the two countries as peaceful unless Mexico should declare war or commit acts of hostility indicative of a state of war, and these orders he faithfully executed. Whilst occupying his position on the east bank of the Rio Grande, within the limits of Texas, then recently admitted as one of the States of our Union, the commanding general of the Mexican forces, who, in pursuance of the orders of his Government, had collected a large army on the opposite shore of the Rio Grande, crossed the river, invaded our territory, and commenced hostilities by attacking our forces. Thus, after all the injuries which we had received and borne from Mexico, and after she had insultingly rejected a minister sent to her on a mission of peace, and whom she had solemnly agreed to receive, she consummated her long course of outrage against our country by commencing an offensive war and shedding the blood of our citizens on our own soil.
The United States never attempted to acquire Texas by conquest. On the contrary, at an early period after the people of Texas had achieved their independence they sought to be annexed to the United States. At a general election in September, 1836, they decided with great unanimity in favor of "annexation," and in November following the Congress of the Republic authorized the appointment of a minister to bear their request to this Government. This Government, however, having remained neutral between Texas and Mexico during the war between them, and considering it due to the honor of our country and our fair fame among the nations of the earth that we should not at this early period consent to annexation, nor until it should be manifest to the whole world that the reconquest of Texas by Mexico was impossible, refused to accede to the overtures made by Texas. On the 12th of April, 1844, after more than seven years had elapsed since Texas had established her independence, a treaty was concluded for the annexation of that Republic to the United States, which was rejected by the Senate. Finally, on the 1st of March, 1845, Congress passed a joint resolution for annexing her to the United States upon certain preliminary conditions to which her assent was required. The solemnities which characterized the deliberations and conduct of the Government and people of Texas on the deeply interesting questions presented by these resolutions are known to the world. The Congress, the Executive, and the people of Texas, in a convention elected for that purpose, accepted with great unanimity the proposed terms of annexation, and thus consummated on her part the great act of restoring to our Federal Union a vast territory which had been ceded to Spain by the Florida treaty more than a quarter of a century before.
After the joint resolution for the annexation of Texas to the United States had been passed by our Congress the Mexican minister at Washington addressed a note to the Secretary of State, bearing date on the 6th of March, 1845, protesting against it as "an act of aggression the most unjust which can be found recorded in the annals of modern history, namely, that of despoiling a friendly nation like Mexico of a considerable portion of her territory," and protesting against the resolution of annexation as being an act "whereby the Province of Texas, an integral portion of the Mexican territory, is agreed and admitted into the American Union;" and he announced that as a consequence his mission to the United States had terminated, and demanded his passports, which were granted. It was upon the absurd pretext, made by Mexico (herself indebted for her independence to a successful revolution), that the Republic of Texas still continued to be, notwithstanding all that had passed, a Province of Mexico that this step was taken by the Mexican minister.
Every honorable effort has been used by me to avoid the war which followed, but all have proved vain. All our attempts to preserve peace have been met by insult and resistance on the part of Mexico. My efforts to this end commenced in the note of the Secretary of State of the 10th of March, 1845, in answer to that of the Mexican minister. Whilst declining to reopen a discussion which had already been exhausted, and proving again what was known to the whole world, that Texas had long since achieved her independence, the Secretary of State expressed the regret of this Government that Mexico should have taken offense at the resolution of annexation passed by Congress, and gave assurance that our "most strenuous efforts shall be devoted to the amicable adjustment of every cause of complaint between the two Governments and to the cultivation of the kindest and most friendly relations between the sister Republics." That I have acted in the spirit of this assurance will appear from the events which have since occurred. Notwithstanding Mexico had abruptly terminated all diplomatic intercourse with the United States, and ought, therefore, to have been the first to ask for its resumption, yet, waiving all ceremony, I embraced the earliest favorable opportunity "to ascertain from the Mexican Government whether they would receive an envoy from the United States intrusted With full power to adjust all the questions in dispute between the two Governments." In September, 1845, I believed the propitious moment for such an overture had arrived. Texas, by the enthusiastic and almost unanimous will of her people, had pronounced in favor of annexation. Mexico herself had agreed to acknowledge the independence of Texas, subject to a condition, it is true, which she had no right to impose and no power to enforce. The last lingering hope of Mexico, if she still could have retained any, that Texas would ever again become one of her Provinces, must have been abandoned.
The consul of the United States at the City of Mexico was therefore instructed by the Secretary of State on the 15th of September, 1845, to make the inquiry of the Mexican Government. The inquiry was made, and on the 15th of October, 1845, the minister of foreign affairs of the Mexican Government, in a note addressed to our consul, gave a favorable response, requesting at the same time that our naval force might be withdrawn from Vera Cruz while negotiations should be pending. Upon the receipt of this note our naval force was promptly withdrawn from Vera Cruz. A minister was immediately appointed, and departed to Mexico. Everything bore a promising aspect for a speedy and peaceful adjustment of all our difficulties. At the date of my annual message to Congress in December last no doubt was entertained but that he would be received by the Mexican Government, and the hope was cherished that all cause of misunderstanding between the two countries would be speedily removed. In the confident hope that such would be the result of his mission, I informed Congress that I forbore at that time to "recommend such ulterior measures of redress for the wrongs and injuries we had so long borne as it would have been proper to make had no such negotiation been instituted." To my surprise and regret the Mexican Government, though solemnly pledged to do so, upon the arrival of our minister in Mexico refused to receive and accredit him. When he reached Vera Cruz, on the 30th of November, 1845, he found that the aspect of affairs had undergone an unhappy change. The Government of General Herrera, who was at that time President of the Republic, was tottering to its fall. General Paredes, a military leader, had manifested his determination to overthrow the Government of Herrera by a military revolution, and one of the principal means which he employed to effect his purpose and render the Government of Herrera odious to the army and people of Mexico was by loudly condemning its determination to receive a minister of peace from the United States, alleging that it was the intention of Herrera, by a treaty with the United States, to dismember the territory of Mexico by ceding away the department of Texas. The Government of Herrera is believed to have been well disposed to a pacific adjustment of existing difficulties, but probably alarmed for its own security, and in order to ward off the danger of the revolution led by Paredes, violated its solemn agreement and refused to receive or accredit our minister; and this although informed that he had been invested with full power to adjust all questions in dispute between the two Governments. Among the frivolous pretexts for this refusal, the principal one was that our minister had not gone upon a special mission confined to the question of Texas alone, leaving all the outrages upon our flag and our citizens unredressed. The Mexican Government well knew that both our national honor and the protection due to our citizens imperatively required that the two questions of boundary and indemnity should be treated of together, as naturally and inseparably blended, and they ought to have seen that this course was best calculated to enable the United States to extend to them the most liberal justice. On the 30th of December, 1845, General Herrera resigned the Presidency and yielded up the Government to General Paredes without a struggle. Thus a revolution was accomplished solely by the army commanded by Paredes, and the supreme power in Mexico passed into the hands of a military usurper who was known to be bitterly hostile to the United States.
Although the prospect of a pacific adjustment with the new Government was unpromising from the known hostility of its head to the United States, yet, determined that nothing should be left undone on our part to restore friendly relations between the two countries, our minister was instructed to present his credentials to the new Government and ask to be accredited by it in the diplomatic character in which he had been commissioned. These instructions he executed by his note of the 1st of March, 1846, addressed to the Mexican minister of foreign affairs, but his request was insultingly refused by that minister in his answer of the 12th of the same month. No alternative remained for our minister but to demand his passports and return to the United States.