Answer:
The answer is B. It is a war fought within a country so it is citizens fighting each other.
Answer:
The expansion of the railroads in the late 1800s was instrumental in helping the US economy boom. It did this in two ways. First, the railroads created a tremendous amount of demand for goods and labor on their own. As the railroads were being built, they needed huge numbers of people to build them.
<span>c. proportional representation</span>
In the late 1800s, American cities suffered from serious environmental pollution due to the smokestack emissions from hydroelectric power plants. The correct answer is D.