Scott, having taken a difficult but relatively…

Scott, having taken a difficult but relatively unprotected route across lava beds and rough land to the south of Lakes Chalco and Xochimilco on August 12, lays open the capital in a series of battles around the right flank of the city defenses, the Battle of Contreras and Battle of Churubusco.

Heavy fighting begins on August 19 at Contreras (also known, particularly in Mexico, as the Battle of Padierna), where Mexican losses are more than ten times those of the sixty American casualties.