Let us for a moment consider the consequences of the retreat of General Taylor to Monterey or of his defeat at Buena Vista. Santa Anna once at Saltillo, will find every thing necessary to refresh his troops, after the sufferings and fatigues of their march. The retreat of the American General will be regarded as a victory for Santa Anna, and it will cause the rancheros of New Leon, Coawilla, and Tamaulipas, to rise _en mass_. General Urrea, it is said, is at the head of ten thousand men near Victoria, so that our army will be shut up in Monterey, and all communications cut off with the Rio Grande. It is true, a portion of General Taylor’s force may be detached to defend some narrow pass between Monterey and Saltillo, and attempt to oppose the advance of Santa Anna. But may not Monterey be turned by Urrea, and thus place himself in the rear of that detachment, while a portion of the Mexican army shall advance in front? Although Santa Anna may not be able to transport his artillery, is it impossible for him to enter the valley of the Rio Grande with his infantry and cavalry, by some circuitous way? I set up no pretensions to being a military critic; my suggestions are merely thrown out for what they are worth, and they may be worth nothing. But I can conceive it possible, for Santa Anna, with his whole army, to enter New Leon and Tamaulipas, and the necessary consequence must be, that all our military stores at Comargo and Matamoras, must fall into his hands. He will sweep the whole valley of the Rio Grande, and in all probability, will not stop there, but cross into Texas, now almost defenceless, there being no force at any point capable of opposing his progress. Admit that these are bare possibilities, these may become probabilities, and probabilities, may become realities. The supposed retreat, or defeat of our army, will change the whole face of the war. Should either of these events take place, (and such is my confidence in General Taylor, that I firmly believe they will not) then the descent on Vera Cruz, and the march to Mexico, under the commander in chief, will have to be abandoned, and a retrograde movement undertaken to the Rio Grande, which cannot be effected without great difficulty and delay.