Nigeria is known for Internet frauds. If you "married" someone that you have not even met in person, start with detective work. Maybe the US embassy can help.
A U.S. citizen needs to file an immigration petition and request that the USCIS notify a U.S. Consulate in the country where his spouse lives. Once the immigration petition is approved, the National Visa Center of the U.S. State Department sends "Packet 3" to the U.S. citizen. After the necessary forms are completed, the alien spouse goes to the U.S. Consulate overseas to apply for an immigrant visa. On the day that the alien spouse enters the United States on an immigrant visa, he/she becomes a U.S. permanent resident.
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