31
Lesson 31 of 84 · Westward Expansion
Environmental Impact of Westward Movement
Historical photographs provide visual evidence. Images of the Civil War, the Great Depression, and the Civil Rights Movement let us see history through the eyes of those who lived it.
Key Facts
1
Primary sources come from the time of the event.
2
Historians use evidence to support claims.
3
Timelines show events in order.
Check Your Understanding
Question 1
1 of 2What is a primary source?