Answer:
After the civil war, a new economy emerged in the USA, which involved the change in techniques and productivity. The business organizations expanded in size and scale. There was a huge increase in production and mechanization. Major sectors which contributed to the economy of the country, which included banking, manufacturing, steel and much more, were all under control of big organizations. This new form of business brought in more money, which eventually helped to change the social classes of many people. A new class of millionaires emerged. Before the civil war, there were only 400 millionaires in USA, while by 1892, the number rose to 4047.