You can apply for a green card as soon as you're legally married to a US citizen.  It can take anywhere from a couple months to a couple years to get approved depending on your location and the circumstances.\n\nOnce you get your green card you're a conditional permanent resident but not a US citizen.  You have to apply two years later for non-conditional permanent residency.  At any point during this process you can be revoked if you're no longer married.  You generally are not subject to revocation if you are the victim of spousal abuse.\n\nUS citizenship is separate and you can generally apply after seven years of legal residency.