Hard to get a job,few freedoms,not enough food to make it , and not being able to worship who they desire.
To escape religious persecution.
US visa.
an airplane
People who emigrate to another country are usually looking to start a better life than they have in their current country.
9000 %
Something will backfire. I would think that there would be fewer opportunities for people to emigrate to the US.
To gain more money.
Nazi persecution drove many extremely talented people to the US.
The "American dream". See related questions for further details.
Very simple: they want to gain many US dollars.
US customs ran a strict quota system where only a certain number of people could enter from any country.
no