The 1848 discovery of gold in California set off a frenzied Gold Rush to the state the next year as hopeful prospectors, called “forty-niners,” poured into the state. This massive migration to California transformed the state's landscape and population.
Steel was important to industrial growth after the civil war because it was used to make steel rails for railroads. <span>n the years between the </span>American Civil War<span> and the end of the nineteenth century the modern U.S. industrial economy developed on the backbone of a good transportation infrastructure mainly railroads that were developed from steel.</span><span>
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From my knowledge, the Huang River is the birthplace of civilization in China. In fact, some of the most ancient settlements in Eastern Asia is situated on the banks of the Huang River. There is a Chinese cliché that says that "the Huang River is the cradle of the Chinese". Now to answer your question, the river provided a source of food and transportation, which encouraged early barter exchange throughout the small villages/tribes of ancient China.