From this moment the tenure of our possessions in New Mexico was no longer considered secure. The troops in that district were not the best disciplined or most docile in the army, and, to the dangers of another sudden outbreak among the treacherous Mexicans, was added the fear of a sudden rising among the Indian tribes who were naturally anxious to find any pretext or chance for ridding the country of a foe whom they feared far more, as a permanent neighbor, than the comparatively feeble half-breeds and Mexicans.
In December of 1846, Lieutenant Richie, who bore despatches to Taylor apprising him of the meditated attack upon Vera Cruz, was seized and slain by the Mexicans whilst on his way to the headquarters, and, thus, Santa Anna became possessed of the plan of the proposed campaign. The Army of Occupation had been sadly impaired by the abstraction of its best material for future action on the southern line under the commander-in-chief. But General Taylor resolved at once to face the danger stoutly, and to manifest no symptom of unsoldierlike querulousness under the injustice he experienced from the government. Nevertheless, prudent in all things, and foreseeing the danger of his command, of the lower country, and of the morale of the whole army, in the event of his defeat,—he exposed the error of the war department in his despatches to the adjutant general and secretary, so that history, if not arms, might eventually do justice to his discretion and fortitude.
The note of preparation preceded, for some time, the actual advent of Santa Anna from San Luis Potosi, and all was bustle in the American encampments which were spread from Monterey to Agua Nueva beyond Saltillo, in order to give him the best possible reception under the circumstances. Wool was encamped with a force at Agua Nueva, in advance on the road from Saltillo to San Luis, about thirteen miles from the pass of Angostura, where the road lies through a mountain gorge, defended, on one side, by a small table land near the acclivities of the steep sierra and cut with the channels of rough barrancas or ravines worn by the waters as they descend from the summits, and, on the other by an extensive net work of deep and impassable gullies which drained the slopes of the western spurs.
This spot was decided upon, as the battle ground in the event of an attack, and the encampment at Agua Nueva, in front of it was kept up as an extreme outpost, whence the scouts might be sent forth to watch the approach of Santa Anna.
