In this Essay, I consider these developments, and ask two questions: First, what are we to make of them? Do these developments signal a retreat from those earlier Supreme Court cases that dismantled the common law tradition in which non-marital births were legally disadvantaged and deeply stigmatized? Put differently, do they suggest a "new illegitimacy" in which non-marital birth status has been resurrected as a salient legal concept? And second, (regardless of how we answer the first question) what are the consequences of the marriage equality movement's interest in illegitimacy? The Essay proceeds in four parts. Part I takes up the first question: does the marriage equality movement's interest in illegitimacy signal the rise of a "new illegitimacy?" Here, I debunk the inherited legal progress narrative that claims that law abandoned the common law's treatment of illegitimacy and its many legal disadvantages in favor of a more liberal legal regime in which those of illegitimate birth were no longer legally disfavored. In doing so, I review Levy v. Louisiana and Glona v. American Guarantee & Liability Insurance Co., the two Supreme Court decisions credited with disrupting the common law tradition disfavoring non-marital births. Though Levy and Glona struck down legal distinctions between marital and non-marital children, I argue that these cases did not render a seachange in our understanding of illegitimacy. Instead, their effects were more modest, and indeed, can be understood as reflecting a preference for marriage and the marital family.