It is a pillar of employment discrimination law that Title VII’s prohibition of “sex” discrimination lacks prior legislative history. When interpreting the meaning of sex discrimination protection under Title VII, courts have stated that it is impossible to fathom what Congress intended when it included “sex” in the Act. After all, the sex provision was added at the last minute by the Southern archconservative congressman Howard “Judge” Smith in an attempt to frustrate the Civil Rights Act’s passage. Courts have often interpreted the sex provision’s passage as a “fluke” that has left us bereft of prior legislative history that might guide judicial interpretation. It is not surprising, then, that Title VII’s sex discrimination prohibition has been rather narrowly construed. This Article rethinks this received narrative and emphasizes its implausibility in light of the pre-Civil Rights Act contributions feminists made to the national discourse on sex discrimination. It considers not only scholarship on Equal Rights Feminists’ role in passing Title VII’s sex provision, but also scholarship on the often-overlooked Working-Class Social and Labor Feminists. The Article also explores the contestations between these two groups over the meaning of sex discrimination. It provides a more complex narrative of the provision’s parentage than the one previously recognized. The Article reframes the narrative by broadening the scope of inquiry in two ways: first, by focusing on Working-Class Social and Labor Feminists’ agitation for equality in the workplace, and second, by looking further back in time in order to reconceptualize debates over workplace equality as formative of the discourse on sex discrimination. The Article begins with early twentieth century contestations over protective labor legislation and argues that Working-Class Social Feminists supported labor regulation based not merely on sex stereotypes, but on their understanding of labor regulation as a means to combat sex discrimination. It continues through the New Deal, when an early sex anti-classification provision was inscribed in federal law by Social Feminists to provide equal pay for men and women. It examines the debates over workplace sex discrimination that reverberated in the decades following World War II and persisted through the early 1960s—when Congress passed the Equal Pay Act and the President’s Commission on the Status of Women issued its report. The Article considers these developments as part of feminists’ sustained efforts to combat sex discrimination, and as stage-setters for the sex provision’s passage. It claims that Working-Class Social and Labor Feminists’ long agitation for women’s equality de-facto constitutes decades’ worth of legislative history for the sex provision. When Congress voted to include “sex” discrimination in Title VII, it was already well aware of its robust meanings, thanks in large part to these feminists’ efforts to ameliorate systemic disadvantages facing women in the workforce. Working-Class Social and Labor Feminists’ actions and ideology should be considered important influences on the context of the sex provision’s birth. As law is the dynamic and indeterminate product of human interaction, its interpretation must account for the complexity of the legacies that infuse it with meaning. To this end, after re-conceiving the history of the sex provision’s birth, the Article suggests this history may provide a richer notion of Title VII sex discrimination, one that emphasizes structural features of the market and requires employers to take affirmative measures to offset the features that often result in discrimination.