But rather quickly after this—between about 1200 and 900 —the building of large earthen pyramids and platforms and the carving of monumental stone sculptures signaled significant changes in this heretofore simple social and political order.
The terminal date of the Late Intermediate Period marked the beginning of the Inca horizon and of the Inca conquests, which spread from the Inca capital, Cuzco, in the southern highlands of what is now Peru.
By 1533, when Francisco Pizarro and his cohorts took over the empire, it extended from what is now the Ecuador–Colombia border to central Chile.
There is evidence—such as the construction of new centres and cities—that this Tiwanaku–Huari phenomenon, at least in many regions, was a tightly controlled political empire.
The horizon and its influences, as registered in ceramics and textiles, died away rather gradually in the ensuing centuries, and it was replaced by the several regional styles and kingdoms of what has become known as the Late Intermediate Period (1000–1438).
This Olmec horizon (i.e., a cultural diffusion that is contemporaneous at widely scattered sites) represents the first climax, or era of “unification,” in the history of Mesoamerican civilization. Among these are the well-known Maya, Zapotec, Totonac, and Teotihuacán civilizations.