I'm U.S. citizen (my only citizenship). I'm a temporary resident of BC while I'm here for school.
I'm just wondering, what happens if I get married in BC or Canada to a fellow U.S. citizen, or really anywhere else in the world.
How does the U.S. find out, for tax or insurance purposes? Am I legally required to report it when I return? Obviously there's a little box that says
 Married but how would they know if I lied if I'm not registered in the United States? Would the Canadian/provincial government inform the U.S./state government?
I know that's a lot of questions so it boils down to I get married in Canada, return to the States. What do I (have to) do next?
I would like answers to be generalizable to any country without residence requirements for marriage.