jobs
thanks that was nice to give me the answer to a test
The same thing that attracted all immigrants: hope, freedom, and opportunity.
about one quarter
Usually for political freedom, religious freedom, money/jobs, family, and/or drought. Opportunity, land, escape religious persecution or legal prosecution. There are probably as many reasons as there were immigrants.
The whole war was quote on quote "good" for the US. Although no war is good, it did bring the US out of the Great Depression. After the war, I assume everything turned back to the way they were in the roaring 20s. Nothing that bad happened until the Vietnam War.
The US, by growing from its initial 13 states to its present 50 states, became a country with increased political and military power, increased opportunity for immigrants, increased economic opportunity for its citizens, and increased opportunity for social, artistic, and scientific progress of all sorts. The US has made tremendous accomplishments which have depended at least in part on the size of the country.
For the most part, immigrants who settled in the US, stayed there. Few returned to their home countries. The main reason for this often was that the US offered a higher standard of living, a great deal of freedom, and the opportunity to become better educated and improve their social & financial situations.
There is one right now.
about one quarter
Most immigrants expect to have more freedoms of religion and a better economic life. They want to live a life better than their lives before. In general terms, immigrants do and have in the past found that the USA offers them more opportunities then their former homelands.
Immigrants come to the US every year. There has never been a single year of US history in which there were no immigrants.
Legal immigrants have to apply to the US government for permission to immigrate. Illegal immigrants sneak in.