Just to clarify -- I already have a green card.
-- foreign alien, non-resident -- i.e. visitor to a state;
-- foreign alien, resident -- temporary worker but living in a state;
-- permanent resident -- same rights as a citizen (supposedly) except for voting -- this is where I am now;
-- US citizen -- after 5 years of living in the US you get the citizenship which gives you the right to vote;
Anyway, that's a summary and the rights are per federal law and of course they do not discuss guns, so that's why I'm asking here ;-)