77
Lesson 77 of 84 · Westward Expansion
The Mexican-American War
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
Cause and effect explain why things happen.
2
Oral histories preserve community stories.
3
Primary sources come from the time of the event.
Check Your Understanding
Question 1
1 of 2What tool puts events in order?