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Lesson 13 of 84 · World History
The Mongol Empire
The Columbian Exchange transferred plants, animals, diseases, and ideas between the Americas and Europe after 1492. Potatoes went to Europe; horses and wheat came to the Americas.
Key Facts
1
Historians use evidence to support claims.
2
Timelines show events in order.
3
Cause and effect explain why things happen.
Timeline
1787
The U.S. Constitution is written
1791
The Bill of Rights is ratified
1803
The Louisiana Purchase doubles the size of the U.S.
Check Your Understanding
Question 1
1 of 2Why do we study history?