Determined to leave no effort untried to effect an amicable adjustment with Mexico, I directed Mr. Slidell to present his credentials to the Government of General Paredes and ask to be officially received by him.  There would have been less ground for taking this step had General Paredes come into power by a regular constitutional succession.  In that event his administration would have been considered but a mere constitutional continuance of the Government of General Herrera, and the refusal of the latter to receive our minister would have been deemed conclusive unless an intimation had been given by General Paredes of his desire to reverse the decision of his predecessor.  But the Government of General Paredes owes its existence to a military revolution, by which the subsisting constitutional authorities had been subverted.  The form of government was entirely changed, as well as all the high functionaries by whom it was administered.

Under these circumstances, Mr. Slidell, in obedience to my direction, addressed a note to the Mexican minister of foreign relations, under date of the 1st of March last, asking to be received by that Government in the diplomatic character to which he had been appointed.  This minister in his reply, under date of the 12th of March, reiterated the arguments of his predecessor, and in terms that may be considered as giving just grounds of offense to the Government and people of the United States denied the application of Mr. Slidell.  Nothing therefore remained for our envoy but to demand his passports and return to his own country.

Thus the Government of Mexico, though solemnly pledged by official acts in October last to receive and accredit an American envoy, violated their plighted faith and refused the offer of a peaceful adjustment of our difficulties.  Not only was the offer rejected, but the indignity of its rejection was enhanced by the manifest breach of faith in refusing to admit the envoy who came because they had bound themselves to receive him.  Nor can it be said that the offer was fruitless from the want of opportunity of discussing it; our envoy was present on their own soil.  Nor can it be ascribed to a want of sufficient powers; our envoy had full powers to adjust every question of difference.  Nor was there room for complaint that our propositions for settlement were unreasonable; permission was not even given our envoy to make any proposition whatever.  Nor can it be objected that we, on our part, would not listen to any reasonable terms of their suggestion; the Mexican Government refused all negotiation, and have made no proposition of any kind.

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 the Del Norte.”  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.