A noncitizen who marries a U.S. citizen does not become a citizen — the marriage buys a faster, friendlier place in a two-part legal process, not a shortcut around it. This guide traces the full arc under the Immigration and Nationality Act: the Form I-130 petition that establishes the relationship, the fork between adjustment of status (Form I-485) and consular processing, the binding Affidavit of Support under INA § 213A, conditional permanent residence and the Form I-751 that removes it, and the shortened three-year naturalization track for spouses under INA § 319(a). It anchors the bona fide marriage requirement in Bark v. INS and Lutwak, explains the Stokes interview and the permanent § 204(c) fraud bar, and details good moral character, continuous residence, physical presence, and the English and civics tests. It maps the I-751 waivers and the VAWA self-petition that protect abused and divorced spouses, and it flags — repeatedly — that forms, fees, and processing times shift constantly and must be verified against current USCIS guidance.