Thick sheets of ice that covered nearly one third of Earth during the last ice age
What are glaciers?
The Aztec built this capital on an island in Lake Texcoco
What is Tenochtitlan?
Giant carved stone heads, possibly portraits of rulers, were left behind by this early civilization
Who are the Olmec?
The Sioux followed this animal across the Great Plains
What is the buffalo?
Worshipped as a god, this Natchez ruler never let his feet touch the ground
Who is the Great Sun?
The land bridge from Siberia led to this present-day U.S. state
What is Alaska?
The Aztec farmed the lake using these floating gardens
What are chinampas?
Without writing, the Inca kept records on these knotted cords
What are quipus?
The Ancestral Puebloans built with this sun-dried brick
What is adobe?
In Iroquois society, these people chose clan leaders and could remove them
Who are the women (clan mothers)?
Instead of the land bridge, some scientists think the first Americans traveled by boat along this route
What is the coastal route?
To make farmland in the rain forest, the Maya cleared trees and drained these
What are swamps?
To farm steep mountainsides, the Inca cut these wide, flat steps
What are terraces?
The spreading of ideas, like farming, from one culture to another
What is diffusion?
The Iroquois League's council was made up of 5 of these specially chosen leaders
What are sachems?
About 5,000 years ago, growing corn, beans, and squash let people stop moving and do this
What is settle in one place?
More than 2 million people still speak their language today, proof they never disappeared
Who are the Maya?
More than 10,000 miles of these, traveled by relay runners, held the Inca empire together
What are roads?
Great Plains tribes couldn't build bark-covered long houses because the Plains had very few of these
What are trees?
They made up most of the Aztec population, yet sat near the bottom of the social pyramid
Who are farmers?
Farming led to settling down, which led to this, which led to the first cities
What is a surplus?
Believing the sun needed sacrifices, the Aztec fought wars to capture these, angering the peoples who later helped the Spanish
What are prisoners?
The Olmec studied the stars to create this, so farmers knew when to plant
What is a calendar?
Same region, different lives: the Northern Paiute could stay put, while the Bannock moved, because the Paiute lived near this
What is water?
This Iroquois constitution told new leaders to think of "the coming generations"
What is the Great Binding Law?