CONTRERAS
When the engineers reported that the fortress on El Peñon could not be carried without a loss of one-third the army, Scott decided to move by the south of the lakes; and Worth accordingly advanced, leading the van, as far as San Augustin, nine miles from the city of Mexico. There a large field of lava—known as the Pedregal—barred the way. On the one side, a couple of miles from San Augustin, the fortified works at San Antonio commanded the passage between the field and the lake; on the other the ground was so much broken that infantry alone could advance, and General Valencia occupied an intrenched camp, with a heavy battery, near the village of Contreras, three miles distant. Scott determined to attack on both sides, and sent forward Worth on the east and Pillow and Twiggs on the west. The latter advanced as fast as possible over the masses of lava on the morning of the 19th, and by 2 P.M. a couple of light batteries were placed in position and opened fire on the Mexican camp.
At the same time, General Persifer Smith conceived the plan of turning Valencia’s left, and hastened along the path through the Pedregal in the direction of a village called San Jeronimo. Colonel Riley followed. Pillow sent Cadwalader’s brigade on the same line, and later in the day Morgan’s regiment was likewise despatched toward that point. They drove in the Mexican pickets and skirmishers, dispersed a few parties of lancers, and occupied the village without loss. Seeing the movement, Santa Anna hastened to Valencia’s support with twelve thousand men. He was discovered by Cadwalader just as the latter gained the village road; and, appreciating the vast importance of preventing a junction between the two Mexican generals, that gallant officer did not hesitate to draw up his brigade in order of battle. So broken was the ground that Santa Anna could not see the amount of force opposed to him, and declined the combat. This was all Cadwalader wanted. Shields’ brigade was advancing through the Pedregal, and the troops which had already crossed were rapidly moving to the rear of Valencia’s camp. Night, too, was close at hand. When it fell, Smith’s, Riley’s, and Cadwalader’s commands had gained the point they sought. Shields joined them at ten o’clock; and at midnight Captain Lee crossed the Pedregal, with a message from General Smith to General Scott, to say that he would commence the attack at daybreak next morning.
It rained all night, and the men lay in the mud without fires. At three in the morning (August 20th) the word was passed to march. Such pitchy darkness covered the face of the plain that Smith ordered every man to touch his front file as he marched. Now and then a flash of lightning lit up the narrow ravine; occasionally a straggling moonbeam pierced the clouds and shed an uncertain glimmer on the heights; but these flitting guides only served to make the darkness seem darker. The soldiers groped their way, stumbling over stones and brushwood, and did not gain the rear of the camp till day broke. Then Riley bade his men look to the priming of their guns and reload those which the rain had wet. With the first ray of daylight the firing had recommenced between the Mexican camp and Ransom’s corps stationed in front and Shields’ brigade at San Jeronimo. Almost at the same moment Riley began to ascend the height in the rear. Before he reached the crest, his engineers, who had gone forward to reconnoitre, came running back to say that his advance had been detected, that two guns were being pointed against him, and a body of infantry were sallying from the camp. The news braced the men’s nerves. They gained the ridge, and stood a tremendous volley from the Mexicans without flinching. Poor Hanson of the Seventh—a gallant officer and an excellent man—was shot down with many others; but the Mexicans had done their worst. With steady aim, the volley was returned; and ere the smoke rose a cheer rang through the ravine and Riley fell with a swoop on the intrenchments. With bayonet and butt of musket, the Second and Seventh drove the enemy from his guns, leaping into his camp and slaughtering all before them. Up rushed Smith’s own brigade on the left, driving a party of Mexicans before them, and charging with the bayonet straight at Torrejon’s cavalry, which was drawn up in order of battle. Defeat was marked on their faces. Valencia was nowhere to be found. Salas strove vainly to rouse his men to defend themselves with energy; Torrejon’s horse, smitten with panic, broke and fled at the advance of our infantry. Riley hurled the Mexicans from their camp after a struggle of a quarter of an hour; and as they rushed down the ravine their own cavalry rode over them, trampling down more men than the bayonet and ball had laid low. On the right, as they fled, Cadwalader’s brigade poured in a destructive volley; and Shields, throwing his party across the road, obstructed their retreat and compelled the fugitives to yield themselves prisoners of war; The only fight of any moment had taken place within the camp. There, for a few minutes, the Mexicans had fought desperately; two of our regimental colors had been shot down; but finally Anglo-Saxon bone and sinew had triumphed. To the delight of the assailants, the first prize of victory was the guns O’Brien had abandoned at Buena Vista, which were regained by his own regiment. Twenty other guns and over one thousand prisoners, including eighty-eight officers and four generals, were likewise captured, and some fifteen hundred Mexicans killed and wounded. The American loss in killed, wounded, and missing was about one hundred men.
Barely taking time to breathe his troops, Smith followed in pursuit toward the city. By ten o’clock in the morning he reached San Angel, which Santa Anna evacuated as he approached. The general-in-chief and the generals of division had by this time relieved Smith of his command; Scott rode to the front, and in a few brief words told the men there was more work to be done that day. A loud cheer from the ranks was the reply. The whole force then advanced to Coyacan, within a mile of Churubusco, and prepared to assault the place.