Why did the California gold rush increased demand for a transcontinental railroad

Which best describes the standards required for foreign producers

Which group had an easier time adapting to american life because of similar backgrounds?

How can changes in technology or consumer demand make it difficult for people to get jobs? by changing the number or kind of jobs available by making it possible for some people to work fewer hours by making it difficult for people to buy what they want by creating a demand for things that are not available