20 President James Polk Calls for War with Mexico

In this address from 1846, President James Polk calls for war with Mexico after receiving news of open warfare between Mexican and U.S. soldiers in “The Thornton Affair.”

James K. Polk, President of the United States at Washington, D.C., to the Congress of the United States. A special message calling for a declaration of war against Mexico.

Washington, May 11, 1846.

To the Senate and the House of Representatives:

The existing state of the relations between the United States and Mexico renders it proper that I should bring the subject to the consideration of Congress. In my message at the commencement of your present session, the state of these relations, the causes which led to the suspension of diplomatic intercourse between the two countries in March, 1845, and the long-continued and unredressed wrongs and injuries committed by the Mexican Government on citizens of the United States in their persons and property were briefly set forth…

In my message at the commencement of the present session I informed you that upon the earnest appeal both of the Congress and convention of Texas I had ordered an efficient military force to take a position “between the Nueces and Del Norte” (Rio Del Norte or Rio Grande). This had become necessary to meet a threatened invasion of Texas by the Mexican forces, for which extensive military preparations had been made. The invasion was threatened solely because Texas had determined, in accordance with a solemn resolution of the Congress of the United States, to annex herself to our Union, and under these circumstances it was plainly our duty to extend our protection over her citizens and soil.

This force was concentrated at Corpus Christi, and remained there until after I had received such information from Mexico as rendered it probable, if not certain, that the Mexican Government would refuse to receive our envoy.

Meantime Texas, by the final act of our Congress, had become an integral part of our Union. The Congress of Texas, by its act of December 19, 1836, had declared the Rio del Norte to be the boundary of that Republic. Its jurisdiction had been extended and exercised beyond the Nueces. The country between that river and the Del Norte had been represented in the Congress and in the convention of Texas, had thus taken part in the act of annexation itself, and is now included within one of our Congressional districts. Our own Congress had, moreover, with great unanimity, by the act approved December 31, 1845, recognized the country beyond the Nueces as a part of our territory by including it within our own revenue system, and a revenue officer to reside within that district had been appointed by and with the advice and consent of the Senate. It became, therefore, of urgent necessity to provide for the defense of that portion of our country. Accordingly, on the 13th of January last instructions were issued to the general in command of these troops to occupy the left bank of the Del Norte. This river, which is the southwestern boundary of the State of Texas, is an exposed frontier. From this quarter invasion was threatened; upon it and in its immediate vicinity, in the judgment of high military experience, are the proper stations for the protecting forces of the Government. In addition to this important consideration, several others occurred to induce this movement. Among these are the facilities afforded by the ports at Brazos Santiago and the mouth of the Del Norte for the reception of supplies by sea, the stronger and more healthy military positions, the convenience for obtaining a ready and a more abundant supply of provisions, water, fuel, and forage, and the advantages which are afforded by the Del Norte in forwarding supplies to such posts as may be established in the interior and upon the Indian frontier.

The movement of the troops to the Del Norte was made by the commanding general under positive instructions to abstain from all aggressive acts toward Mexico or Mexican citizens and to regard the relations between that Republic and the United States as peaceful unless she should declare war or commit acts of hostility indicative of a state of war. He was specially directed to protect private property and respect personal rights.

The Army moved from Corpus Christi on the 11th of March, and on the 28th of that month arrived on the left bank of the Del Norte opposite to Matamoras, where it encamped on a commanding position (Fort Brown), which since been strengthened by the erection of fieldworks. A depot has also been established at Point Isabel, near the Brazos Santiago, 30 miles in rear of the encampment. The selection of his position was necessarily confided to the judgment of the general in command.

The Mexican forces at Matamoras assumed a belligerent attitude, and on the 12th of April General Ampudia, then in command, notified General Taylor to break up his camp within twenty-four hours and to retire beyond the Nueces River, and in the event of this failure to comply with these demands announced that arms, and arms alone, must decide the question. But no open act of hostility was committed until the 24th of April. On that day General Arista, who had succeeded to the command of the Mexican forces, communicated to General Taylor that “he considered hostilities commenced and should prosecute them.” A party of dragoons of 63 men and officers were on the same day dispatched from the American camp up the Rio del Norte, on its left bank, to ascertain whether the Mexican troops had crossed or were preparing to cross the river, “became engaged with a large body of these troops, and after a short affair, in which some 16 were killed and wounded, appear to have been surrounded and compelled to surrender.

The grievous wrongs perpetrated by Mexico upon our citizens throughout a long period of years remain unredressed, and solemn treaties pledging her public faith for this redress have been disregarded. A government either unable or unwilling to enforce the execution of such treaties fails to perform one of its plainest duties.

Our commerce with Mexico has been almost annihilated. It was formerly highly beneficial to both nations, but our merchants have been deterred from prosecuting it by the system of outrage and extortion which the Mexican authorities have pursued against them, whilst their appeals through their own Government for indemnity have been made in vain. Our forbearance has gone to such an extreme as to be mistaken in its character. Had we acted with vigor in repelling the insults and redressing the injuries inflicted by Mexico at the commencement, we should doubtless have escaped all the difficulties in which we are now involved.

Instead of this, however, we have been exerting our best efforts to propitiate her good will. Upon the pretext that Texas, a nation as independent as herself, thought proper to unite its destinies with our own, she has affected to believe that we have severed her rightful territory, and in official proclamations and manifestoes has repeatedly threatened to make war upon us for the purpose of reconquering Texas. In the meantime we have tried every effort at reconciliation. The cup of forbearance had been exhausted even before the recent information from the frontier of the Del Norte. But now, after reiterated menaces, Mexico has passed the boundary of the United States, has invaded our territory and shed American blood upon the American soil. She has proclaimed that hostilities have commenced, and that the two nations are now at war.

As war exists, and, notwithstanding all our efforts to avoid it, exists by the act of Mexico herself, we are called upon by every consideration of duty and patriotism to vindicate with decision the honor, the rights, and the interests of our country.

The most energetic and prompt measures and the immediate appearance in arms or a large and overpowering force are recommended to Congress as the most certain and efficient means of bringing the existing collision with Mexico to a speedy and successful termination.

In making these recommendations I deem it proper to declare that it is my anxious desire not only to terminate hostilities speedily, but to bring all matters in dispute between this Government and Mexico to an early and amicable adjustment; and in this view I shall be prepared to renew negotiations whenever Mexico shall be ready to receive propositions or to propositions of her own.

I transmit herewith a copy of the correspondence between our envoy to Mexico and the Mexican minister for foreign affairs, and so much of the correspondence between that envoy and the Secretary of State and between the Secretary of War and the general in command on the Del Norte as is necessary to a full understanding of the subject.

JAMES K. POLK.

James K. Polk, President of the United States at Washington, D.C., to the Congress of the United States. “A special message calling for a declaration of war against Mexico.” Washington, May 11, 1846.

Carl Nebel’s Lithograph depicting the “Battle of Palo Alto” north of present-day Brownsville, Texas. The background landscape more closely resembles the interior of northern Mexico or western Texas.