According to current immigration law, employers have to regularly check the paperwork for a foreign worker, and must keep it on file for three years after hire or a year after termination, whichever period is longer. Employers can't, however, be held responsible for well-forged paperwork.

If you have any serious questions about immigration law, consult an attorney who specializes in the field. For professional reasons they have to keep themselves up-to-date on all the twists and turns on immigration law, and are far more likely to be able to help you than anyone else.

Immigration law requirements are often tied to an individual's occupation. If you are a nurse, for example, you'll have different requirements to get a visa than an engineer might have. In most cases, you'll be allowed to bring your family to the US for the duration of the visa.