Scott landed at the head of twelve thousand men to make the conquest of Mexico. His first objective point was the famous Castle of San Juan de Ulua, the dragon which guarded Vera Cruz, and lay in the path of the little army to the capital. On the 12th of March, 1847, the investment of the city was completed. Ten days later the batteries opened fire upon the castle and city; and after four days of the most incessant hammering, an assault by the besieging army was planned; but the governor of the city proposed to surrender. In just twenty days after the little army landed, the Stars and Stripes floated victoriously over the city, and over the invulnerable castle. The amazing rapidity with which the siege operations were carried forward confounded the enemy. With the bitter experience of Monterey as a specimen of the spirit of the assailants, they were not disposed to go through the form of attempting to repel an assault. The dragon in the path of the victorious army was demolished, and the road to Mexico was open to the conquerors. Preparations were made immediately for the grand march to the Halls of the Montezumas. On the 1st of April Lieutenant Grant was appointed quartermaster of the Fourth Regiment--a position requiring peculiar abilities in the incumbent. He was selected for this important office because he was a careful, substantial, and energetic person; and he continued to fill it to the entire satisfaction of his superiors until the close of the war. Early in April the advance was sent forward on the road to Jalapa. Santa Anna, routed at Buena Vista, had gathered together another army of fifteen thousand men, and intrenched himself in a strong position on the heights of Cerro Gordo, effectually commanding the only passage through the mountain gorges to the capital. Six days after the appearance of the advance before this formidable position, Scott, with the main army, arrived. The stronghold was immediately stormed, and after a series of brilliant operations the position was carried. Three thousand prisoners and forty-three bronze guns were captured, besides seven standards and Santa Anna's private baggage. Signor Jimen, in the official journal of Mexico, defended the generalship of Santa Anna, and innocently attributed the terrible defeat to "inevitable misfortune, the result of the tactics of the invaders." The Mexicans were flanked by the passage of a portion of the American forces through a ravine which had never before been crossed, and which was deemed impassable. The "tactics" were doubtless the sore trial of the Mexicans, and when I think of the material of which our officers were composed, I am hardly supprised at the magnitude of their achievements. Scott believed in councils of war, and had the benefit of the united thought of his brilliant officers.