"The changes that led to the loss of the balanced oppositions began when the Azteca"

Anzaldúa's account of pre-Columbian history is compressed--and it's written from a specific viewpoint.  For much more detail and debate, there are several great online resources including Ancient Web and History.com.  In this photo, Aztec-style dancers perform in modern-day Chapultepec Park, which is built on the site where the Azteca-Mexica settled in 1248.

Chapultepec Park Today
Public DomainChapultepec Park Today