40
Lesson 40 of 84 · Westward Expansion
Building the Transcontinental Railroad
The Roman Empire spread across Europe, North Africa, and the Middle East. Rome built roads, aqueducts, and legal systems. Architectural innovations like the arch and dome still influence building today.
Key Facts
1
Timelines show events in order.
2
Cause and effect explain why things happen.
3
Oral histories preserve community stories.
Check Your Understanding
Question 1
1 of 2Which is a secondary source?