A History of the World: Chapter 16: The Americas

Central America is an isthmus, a narrow piece of land that connects two larger areas of land.

The Amazon carries the highest volume of water of any river on Earth.

Today, the Americas are not linked to the world's other landmasses, but they were long ago.

The first crops that early Americans grew included peppers, pumpkins, squash, gourds, beans, and potatoes. Corn, also known as maize, took longer to develop.

Growing and trading crops helped early Americans form more complex societies.

The causes for decline might have been a severe drought—a long period with little rainfall—or revolts by populations that had used up the natural resources of the area. Whatever the reason, the cities were abandoned.

In spite of everything they achieved the Chavín and the Moche did not build empires.

A sinkhole is an area where the soil has collapsed into a hollow or depression. Sinkholes gave the Maya access to a network of underground rivers and streams.

They developed calendar systems to predict eclipses and to schedule religious festivals.

The Aztec relied on strong kings, or emperors, who claimed to be descended from the gods.

Government officials stored food when there were good harvests and distributed it when harvests were poor.

The Inca used a quipu, a rope with knotted cords of different lengths and colors. This was a useful tool for both mathematics and for record keeping.

When they traveled, they built igloos, temporary homes made from cut blocks of hard-packed snow.

In time, the Navajo became farmers and settled in villages made up of square wooden homes called hogans.