This article examines how the classical liberal “march of progress” has, particularly in recent decades, taken the form of a queue that shapes how marginal identities and practices can become recognizable as valid and worthwhile by following the form of what came before. Based on ethnographic fieldwork with people practicing polyamory, or consensual non-monogamy, who often referred to polyamory as their sexual orientation, I argue that the expansion of the category of sexuality illuminates contemporary mechanisms of subject formation in American late liberalism. However, an exclusive focus on recent decades and the rise of identity politics is insufficient for understanding the dramatic rise of both polyamory and the increasing capaciousness of the sexual orientation framework. I thus argue further that, more than simply demonstrating the proliferation of identities taking shape within an identity political framework, discourses around polyamory also highlight the powerful demands of civility and respectability made of subjects of sexual orientation, which requires a longer historical view of the interconnections of marriage, monogamy, and whiteness as constitutive of social, political, and legal recognition in the U.S.