I believe you are asking if it is legal for an employer to hire a legal immigrant over a American citizen. By "legal immigrant," I assume you mean one who is authorized to work in the United States. Yes. As long as the person hired is legally authorized to work in the United States, his citizenship is irrelevant. Keep in mind that it is illegal in many jurisdictions for an employer to discriminate against a potential employee on the basis of national origin.
If you mean is it legal to HIRE a legal immigrant, then yes, certainly. It is ILLEGAL for employers to prefer US citizens over legally admitted immigrants. everyone legally allowed to work in the USA competes with every other legal worker. The ILLEGALS must sit out the competition and not work anywhere.
You shouldn't be able to "hire" anyone. This is the job of the federal government.
she's not a u.s. citizen yet but she's a legal immigrant and legal immigrants can work. then(if you're a u.s. citizen) after three years being married to you she can become a u.s. citizen. If she was here illegally when you married her and have not filed any paperwork to adjust her status the she is subject to deportation whether she is married to you or not. If you think the green card application is expensive just wait to you see the bills you face if she gets caught and you need to hire a lawyer to keep from getting her deported.
Don't no
As an employer, you need to insure that your prospective hire has a legal right to work in the United States. If the person is not a citizen, then you need to find out if you can provide a legal visa for the employee. If not, then you have to terminate her.
It may depend on how the question is asked. You DO Have to give them your Date of Birth.
yes
yes its legal
Yes
It's legal but is it ethical?
If you are taking it without a legal prescription YES they can choose not to hire you.
Yes.