They bought complex social and economic changes that led to riots, strikes and the emergence of the unions.
They showed no concern for their workers, keeping their wages at a minimum, and reduced them as they felt fit. Many of them suffered poor standards of living while the Robber Barons lived luxurious lives.
Because of them today money goes around the world so that people could either become rich or poor
Among the choices posted, the best and only sensible answer is: the search for food items. The Asians who crossed the Bering Strait did not need to spread religion, to bring slaves from Africa nor the desire to conquer new peoples.
Well an obvious answer would be slavery, depending on how late you're talking. After slavery ended, the country began what is known as the "industrial revolution". The north had already begun industrializing for a while, but in the 1870's and beyond, things ramped up quite a bit. Factories for clothes, shoes, farming equipment, packaged foods, and etc. became more popular. You also had coal mines, railroads, and steel mills. This showed the country was moving in the direction of mass production, and moving away from agricultural ways of living. This also meant child labor, which led to many child labor laws in the later years. This also meant many moved out of farming communities, and into larger, noisy, and crowded cities. Many immigrated to the US to take advantage of that, which led to some tension between communities.
Hope that helps!
Farming scenes are very difficult to set up, especially to make them seem peaceful. I had to help make a farm scene for a play and it was very hard to do with everyone moving stuff around.