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.