What pushed the Chinese out of China?
China is very overpopulated. It is very crowded having a population of 1,344,130,000. This heavy population has caused them to to have a one child policy. You can't have more than one child, and if you do... It must be killed.
There were several job opportunities, most immigrants went into steel, meat packing, and mining. 24% of the working population were immigrants. At this time, industrialization was taking place in the West of the US because of the gold rush. They were also pulled in by the fact of the democratic government and the education opportunities that America had to offer.