A foreign national who enters the US legally and subsequently marries a US citizen is eligible to apply for a green card.
The application normally contains several applications and petitions that can be submitted immediately after the legally registered marriage takes place. The applicant will receive an unrestricted employment authorization document and advance parole travel document 6-8 months after the applications are filed.
A foreign national who enters the US legally and subsequently marries a green card holder is also eligible to apply for a green card. However, once the process is started, the foreign national often has to wait longer for completion of the green card processing. While the process is ongoing, the spouse of a green card holder must either maintain his or her legal status in the U.S. or wait for the green card to process from abroad.