The answer is B. None of the other choices were a result of that war.
Answer:
People could finally travel by train across the entire country.
Explanation:
US railway services by 1870 had undergone a great amount of development. This form of transport was becoming more popular as it helped in the movement of people and heavy goods such as agricultural products in bulk.
People could finally travel by train across the entire country due to rail roads being present in all states of the country.
Southern slaveholders did not want the Congress to take the power over, so slave trade while controlling foreign affairs. So they only let the Congress have power over trade, excluding slave trade, for next twenty years.
