Though the United States were the aggrieved nation, Mexico commenced the war, and we were compelled in self-defense to repel the invader and to vindicate the national honor and interests by prosecuting it with vigor until we could obtain a just and honorable peace. On learning that hostilities had been commenced by Mexico I promptly communicated that fact, accompanied with a succinct statement of our other causes of complaint against Mexico, to Congress, and that body, by the act of the 13th of May, 1846, declared that "by the act of the Republic of Mexico a state of war exists between that Government and the United States."