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the answer is a. National markets increased as goods could be sold across the country more easily.
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Major effect of the growing railroad industry is that National markets increased as goods could be sold across the country more easily.
The growth in rail-road construction between 1860 and 1900 marks the beginning of the significant industrial era for the nation.
- The development lead to more construction of more Rail-road across the states and these lead to more companies getting involved in the construction.
- The involvement leads to increased demand of materials such as iron, steel, copper, machine tools etc
In conclusion, these want and demands expanded the market and lead to an increase in National markets.
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