With the Molino del Rey in American hands, there was only one major fortified point between Scott's army and the heart of Mexico City: a fortress at the top of the Chapultepec hill. The fortress was also Mexico's Military Academy and many of the young cadets fought in its defense. After a day of pounding Chapultepec with cannons and mortars, Scott sent parties with scaling ladders to storm the fortress. Six Mexican cadets fought valiantly to the end: the Niños Héroes
, or "Hero boys" are honored in Mexico to this day. Once the fortress fell, the city gates were not far behind and by nightfall General Santa Anna had decided to abandon the city with those soldiers that he had left. Mexico City belonged to the invaders and Mexican authorities were ready to negotiate. The Treaty of Guadalupe Hidalgo
, approved in May of 1848 by both governments, ceded vast Mexican territories to the USA including California, New Mexico, Nevada and Utah.