Mexico denounces the war as being aggressive on our part, but in all the official State Papers of the high functionaries of that Republic, (I do not refer to subordinate officers or generals,) in all their manifestos, that aggression is distinctly declared to _be the annexation of Texas_. It was on this ground, that she put an end to all diplomatic intercourse, after having previously announced that she would consider annexation as equivalent to a declaration of war, on our part. It was on this ground, that she refused to _resume_ a diplomatic intercourse, and enter into negotiation for a peaceful adjustment of existing differences, until satisfaction should first be made for the alleged wrong. She has not limited her complaints of alleged aggression to the march of our troops to the Rio Grande; her complaint is, the being deprived of her province of Texas, which she will never renounce; and she declares her determination never to listen to overtures of peace, until that province shall be evacuated by us. Has she, on any occasion, shown a willingness to accept any other boundary than the Sabine? I have seen no intimation of this kind, emanating from her President or Congress. The contrary is unchangeably persisted in.[4] In fact, it could not occur while she persists in her right to the whole of Texas. The annexation is the _casus belli_ on the part of Mexico—the paramount consideration—every thing else, is but incidental, or subordinate. The very idea of fixing any other boundary, would imply a relinquishment of her claim. Footnote 4: There is no distinct assertion of boundary in any of her official papers down to the _war proclamation_ of the 23d of April, 1846.