Lecture 37: The Americas in the Later Agrarian Era
increasing warfare triggered by overpopulation (the heartland, near Tikal,
may have been more densely settled in 800 C.E. than today), deforestation,
erosion, and declining soil fertility. But Mesoamerican civilizations would
revive. By 1492, there existed in Central Mexico a huge imperial civilization
based on Tenochtitlán (now Mexico City). The Aztec rulers of Tenochtitlán
exacted tributes from neighboring regions and cities. Tenochtitlán was one
of the most magni¿ cent cities in the world; with nearby towns, it may have
had a population of 2 million people. We have a wonderful description of it
in the writings of Cortés’s lieutenant, Bernal Díaz.In the Andes region, Agrarian civilizations evolved in modern Ecuador, Peru,
and Chile. The main crops were maize, potatoes, and quinoa, and the main
animal domesticates were llama, alpaca, and guinea pig. Along the coast,
substantial communities emerged in the 2nd millennium B.C.E. They built
irrigation systems and ceremonial pyramids.Incipient Agrarian civilizations emerged in the 1st millennium B.C.E. They
exploited different ecological zones extending from the coast, with its arid
climates and rich ¿ sheries, to the mountain highlands, with their crops of
peanuts, potatoes, cotton, and beans. Towns À ourished with populations of
more than 10,000 and large public buildings. In the 1st millennium C.E., the
Moche state, near the coast of northern Peru, integrated highland and lowland
regions, organizing irrigation and managing exchanges between regions
using humans, llama, and alpaca. Images show evidence of class hierarchies,
warfare (once again we ¿ nd pictures of rulers inspecting captives), and
organized labor. The Moche state collapsed sometime in the 7th century C.E.,
after a series of spectacular natural disasters ruined irrigation systems and El
Niño–driven climate changes ruined the rich anchovy ¿ sheries. No writing
is known from these early states. However, by 1500 C.E. the Inka had
developed a system based on knotted strings, or “quipu.” This worked well
for accounting, but probably less well for recording history or literature.Were the two major American zones of Agrarian civilization as integrated as
those of Afro-Eurasia? Maize diffused to South America from Mesoamerica
by about 2000 B.C.E. and, when the Spanish arrived, their diseases reached
Peru before any of their soldiers did, so there were clearly contacts of some
kind. Nevertheless, contacts were much less intense than those linking