Sure you can, although there are certain jobs with defense contractors like Lockheed (or much smaller companies of course) for which you need a security clearance. You can't get one of those without being a citizen, but that's the only restriction.
Phil
Absolutely, but non-citizens need a work visa or a green card issued by the government (the Immigration office).
Yes. He must apply for a work visa in order to work legally.
lots of paper work
kinda... If non-Americans have US citizenship, then they can, but without, NO
Yes apart from the benefit of right to vote, freedom to travel abroad etc for work in the judiciary also US citizenship is mandatory.
Your friend don't need a citizenship if he is just on a vacation.
Someone with dual citizenship should be able to enter and reside in each country in which citizenship is held without obtaining a visa. That is part of what citizenship is about - the right to enter and travel freely in your country of citizenship.
No you must be a citizen.
Yes, the child does acquire US citizenship by the law of land. Just don't forget to get the birth certificate and apply for a US passport for the child.
I am holding us and Canadian citizenship and have social security no,can i still work in Canada.
If you apply for citizenship in another country your US citizenship is automatically revoked. The US does not recognize dual citizenship. You revoke it in writing at a US embassy, outside the US.
Yes, The residents of US territories have US citizenship
The US recognizes dual citizenship.
Japan does not allow dual citizenship; when the person who holds dual citizenship of Japan and another country reaches the age of majority, Japanese officials ask them to surrender one of the nationalities. So, if you have not renounced your US citizenship yet and can apply for (or have) a valid US passport, you do not need a visa to move to the US for work or any other purposes.