This Essay reads the U.S. Supreme Court’s decision in United States v. Windsor, which technically rested on equal protection grounds, through the lens of the fundamental right to marry. It shows that Justice Kennedy, who authored the majority opinion, espoused a view of marriage that suggests that the fundamental right to marry as presently understood safeguards a right that applies to same-sex couples. Yet this Essay argues that even if the Court ultimately rejects the fundamental rights claim, understanding Windsor’s right-to-marry dimensions reveals why the case for marriage equality has resonated so strongly. Over the past few decades, LGBT advocates have located same-sex relationships within ascendant marital norms. They have situated same-sex couples within marriage’s private welfare function and have emphasized the unique public recognition that marriage bestows and that same-sex couples seek. In Windsor, the Court absorbed this LGBT rights work by contextualizing same-sex couples within a contemporary model of marriage in which marriage’s private welfare function and its public recognition dimensions are mutually reinforcing. Ultimately, this specific understanding of the right to marry will likely guide the Court’s equal protection, rather than substantive due process, analysis when it one day determines the constitutionality of state marriage prohibitions. Under the view of marriage adopted in Windsor, the Court will likely find that same-sex couples are similarly situated to different-sex couples, that governmental interests rooted in biological procreation and dual-gender parenting are unrelated to marriage’s primary purpose, and that separate nonmarital regimes fail to offer equal treatment.