Question

which region of the country has the greatest concentration of railroad lines?
☑ northeast
○ northwest
○ southeast
○ southwest
complete
which region seemed to provide the greatest obstacle to railroad expansion?
○ the great lakes
○ the appalachians
○ the mississippi river
○ the rocky mountains
done

Explanation:

For the first question, the map shows the Northeast (northeastern U.S.) is fully covered in the railroad color, indicating the highest concentration. For the second question, the Rocky Mountains (a large, rugged mountain range in the western U.S.) presented extreme topographical challenges that made railroad construction far more difficult compared to the other options, acting as the greatest obstacle to westward railroad expansion.

Answer:

1. Northeast
2. The Rocky Mountains