Answer:
They became essential especially during the "Age of New Imperialism" (1870 s). It aided the locomotion that was needed for great empires. Europe became more powerful because the railroads, together with money, allowed them to control other countries, especially the agrarian ones.
It allowed them to gain control of other nation's natural resources as well. One example of this are the "trunk lines" which connect the commercial centers with the seaports in Africa. This allowed the gold fields and diamond fields to be directly connected to the port. This were then destined to the factories and markets in Europe.
Step-by-step explanation:
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