Abstract In the 1910s, U.S. social reformers advocated for labor laws to protect women who worked in factories. The laws included bans on women working at night. In New York, a small contingent of night-working women who had lost their jobs objected. Arguing that the laws were paternalistic and harmful, they formed the Women’s Equal Opportunity League. The group opposed all single-sex laws and ultimately won repeal of New York’s night work ban for printers, elevator operators, and transit workers. Night work was the stage on which reformers’ ideas about the greater good conflicted with arguments for women’s autonomy. Whether and what kind of work women should do at night was a conflict about class, motherhood, and self-determination. This article profiles three leaders of the Women’s Equal Opportunity League—printer Ella M. Sherwin, transit guard Margaret Hinchey, and streetcar ticket agent Mary A. Murray. All three were devoted union members whose opposition to women-only laws made them dissidents within their unions. They remained shift workers their entire lives while lobbying state legislatures and Congress to demand formal legal equality for women. Histories of the early Equal Rights Amendment (ERA) have emphasized the support of upper- and middle-class women. These working-class women, who had long opposed protective legislation, later demanded the ERA—not in spite of the prospect that it would nullify single-sex labor laws, but because they hoped it would. Theirs was a minority position, and paying attention to it reveals the complexity of class conflict at the root of a feminist dispute which persisted long into the twentieth century.