How many miles of railroads were constructed as of 1890?
A. 98,000 miles
B. 136,000 miles
C. 161,000 miles
D. 232,000 miles

What invention is Henry Ford know for?
A. Model T
B. Railroad
C. Lightbulb
D. Airplane

Factories

What industry did Andrew Carnegie expand?
A. Agriculture
B. Steel
C. Energy
D. Manufacturing