How can an alien become a legal permanent U.S. resident or green card holder?

To become a legal permanent resident, an alien must first be admitted as an immigrant. There are two basic methods for obtaining an immigrant visa: 1) through family relationship with a U.S. citizen or legal permanent resident, or 2) through employment. Specific information is available from the U.S. Citizenship and Immigration Services (USCIS) in the United States.