US Presidency
1847

It is not to be expected that Mexico, after refusing to establish such a line as a permanent boundary when our victorious Army are in possession of her capital and in the heart of her country, would permit us to hold it without resistance. That she would continue the war, and in the most harassing and annoying forms, there can be no doubt. A border warfare of the most savage character, extending over a long line, would be unceasingly waged. It would require a large army to be kept constantly in the field, stationed at posts and garrisons along such a line, to protect and defend it. The enemy, relieved from the pressure of our arms on his coasts and in the populous parts of the interior, would direct his attention to this line, and, selecting an isolated post for attack, would concentrate his forces upon it. This would be a condition of affairs which the Mexicans, pursuing their favorite system of guerrilla warfare, would probably prefer to any other.