How to marry a illegal immigrant (alien) and how to obtain an ID for them?

If your intention is to file paperwork for the deported illegal alien, you will have to go the country where the alien now resides and marry. After marriage, you can return to the U.S. and file a "stand alone" Form I-130 petition for alien relative. After it is approved, you will then take the next step by filing the application for immigrant visa and affidavit of support and all the supporting documents to the National Visa Center "NVC". You are strongly advised however, not to file anything without first speaking to an experienced immigration attorney. Apart from filing the I-130 petition, an alien who has been deported from the U.S. must also apply for a waiver of deportation in order to be eligible to return. You must first understand the reasons for his deportation because, not all grounds of deportation are eligible to return to the U.S. Finally, you must advise the alien not to attempt to return illegally into the U.S. without DHS authorization. Whatever chances the alien may have to getting a green card in future is severely diminished by further acts of immigration violations.

If that person re-entered the U.S. illegally again, after being deported, there is no relief for that person no legal pass to a green card right now. If that person was deported once and remains outside the U.S., and if there is no criminal history otherwise, he may be eligible for a waiver of a ten-year bar in order to be able to re-enter the U.S. if he is married to a U.S. citizen. This is not a simple process, however, and the waiver is not guaranteed, so in the worst case scenario, if this person has done nothing else wrong (no criminal history other than this one deportation), he may be stuck outside the US for ten years. If there is criminal history, or if he entered the U.S. illegally more than once, the truth is that he may never be able to return legally to the U.S. It all depends on the individual circumstances of this person.