CONTRERAS, a hamlet about eight miles S.W. of the city of Mexico. It was in the vicinity of this small town that Maj Gen. Winfield Scott, with some 4,200 American troops of his column in the southern campaign of the war between Mexico and the United States (1846-48) encountered first the difficult barriers of pedregal (lava beds) and lakes surrounding his ad versary's capital. In this particular defence Gen. Santa Anna employed about 7,00o Mexicans, although possibly three times that number occupied forts and redoubts at critical points else where about the city. Scott, having circled to the south of his goal, found, upon determined reconnaissance, that San Antonio directly in his front was so heavily defended that an assault might cripple him. He decided to build a road over the pedregal toward the west, thereby pinching out Santa Anna's strong posi tion. Accordingly on Aug. 19, 1847, Maj.-Gen. G. J. Pillow's division was ordered to supply working parties and push forward the road the engineers were building and to brush aside any small resistance without bringing on a general engagement. Pillow, however, after being stopped, decided to attack. In the pre mature struggle only the natural team work of the trained leaders, such as Riley, Smith and Magruder, saved defeat until Scott, coming upon the field, ordered a concentration of his forces at San Geronimo, the key position. Darkness, aggravated by a storm, cut Scott off from the knowledge of the whereabouts of his troops. In the early morning, Aug. 20, Capt. Robert E. Lee, after a voluntary, desperate ride across the pedregal, bore Scott the intelligence that Brig.-Gen. P. F. Smith had found a way to the enemy's rear and would attack at dawn. Scott prepared Twiggs to co-operate in front, and, as a result, San Geronimo was taken in front, flank and reverse in less than 20 minutes. San Antonio was evacuated and the battle of Churubusco begun the same day. The cannon and ammunition captured from the Mexi cans aided Scott materially. The Mexican losses were approxi mately 1,50o as against less than Ioo Americans.
BIBLIOGRAPHY.,—J. H. Smith, The War with Mexico, vol. i. (1919) ; Bibliography.,—J. H. Smith, The War with Mexico, vol. i. (1919) ; G. B. McClellan, The Mexican War Diary (1917) ; C. M. Wilcox, His tory of the Mexican War (1892) ; W. A. Ganoe, The History of the United States Army (1924) ; Original Correspondence and Reports in Old Files Section, Adjutant General's Office (Washington, D.C.) (W. A. G.)