Understand how people may have first reached the Americas.

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Objectives

• Understand how people may have first reached the
  Americas.
• Find out how people learned to farm.
• Explore the civilizations of the Mayas, Aztecs,
  and Incas.

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Terms and People

• glacier thick sheet of ice
• irrigate to water crops by channeling water
  from rivers or streams
• surplus excess quantity that is left over
• civilization an advanced culture in which
  people have developed cities, science, and
  industries

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How did early civilizations develop in the
Americas?
Scientists have several theories about how people
first came to the Americas.
One theory says people migrated over a land
bridge.
One theory says people came by boat.
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Between 10,000 and 100,000 years ago, much of the
world was covered by glaciers.
As more of the worlds water froze, the level of
the oceans dropped, and a land bridge appeared
between Siberia and Alaska.
Today, that land bridge lies under a narrow
waterway called the Bering Strait.
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Many scientists think people first came to North
America between 20,000 and 30,000 years ago.
They believe that hunters crossed the land bridge
in pursuit of animals such as the woolly mammoth.
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Over thousands of years, people spread across
North and South America.
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The coastal-route theory says that people crossed
the arctic waters by boat and traveled southward
along the Pacific coast.
Many Native American groups dismiss both theories
in favor of their own creation stories.
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For centuries, early humans could fill most of
their needs by hunting, but then many of the
larger animals began to disappear.
Hunters became gatherers, traveling around and
searching for wild plants and small game.
hunters
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About 8,000 years ago, gatherers in Mexico began
growing food, including squash and lima beans.
This discovery of farming meant that families no
longer had to wander in search of food.
Farmers began to irrigate and learned to raise
animals.
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The population grew rapidly, and once they began
to produce surplus food, Native Americans started
trading with others.
Some farming communities grew into cities, which
became centers of government and religious life.
With the development of cities came the
beginnings of civilization.
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Over the centuries, several civilizations rose
and declined in the Americas

• the Mayas
• the Aztecs
• the Incas

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The Mayas The Mayas
Time Period Between A.D. 250 and A.D. 900
Location Present-day Mexico and Central America
Achievements Built splendid cities Developed arts, a system of government, and a written language Created the most accurate calendar known until modern times
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Chichen Itza
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Around A.D. 900, the Mayas began to abandon their
cities, perhaps because of disease or
overpopulation.
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The Aztecs The Aztecs
Time Period Between 1325 and 1521
Location Present-day Mexico
Achievements Built the city Tenochtitlán, which may have been the biggest city in the world at the time Built Tenochtitlán on islands in a large lake and connected them by stone roadways
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On a series of islands in a large lake, the
Aztecs built a great capital city, Tenochtitlán,
on the site of present-day Mexico City.
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Tenochtitlán Tenochtitlán
Population More than 200,000 people lived there at the citys height.
Farming Many farmers raised crops on floating platforms.
Religion Religion dominated Aztec life. The center of the city had dozens of temples that honored Aztec gods. The Aztecs practiced human sacrifice as an offering to their gods.
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During the 1400s, Aztec armies brought half of
modern-day Mexico under their control.
The Aztecs were harsh rulers, and their subjects
would eventually turn on them when Europeans came
to conquer the region.
Aztecs
Europeans
subjects
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The Incas The Incas
Time Period Between the early 1400s and 1533
Location Down the coast of South America along the Andes, across the Atacama desert, and to the fringes of the Amazon rain forest
Achievements Built the largest empire in the world in the 1400s Buildings of huge stones shaped to fit together Roads, walls, canals, and bridges Fine weavings and metalwork
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Machu Picchu
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