This article explores working-class families’ modes of collective action in Argentina’s first national railroad strike in 1917. While historical literature has largely focused on the role of railroad unions in labor politics, insufficient attention has been paid to community mobilization and family support in this labor protest. This study offers a fresh approach to this massive social conflict by reconstructing female public participation in its events. The study also takes gender as a category for analyzing the cultural meanings of sexual difference, which shaped both the political sociability of working-class families and their language of rights. Drawing on a variety of sources, such as trade-union journals, the left-wing press, major national newspapers, company documents, official records, and memoirs of labor militants, the essay contends that the great railroad strike was in essence a family enterprise. It represented a landmark in the making of the railwayman as the male breadwinner at the same time that it prompted an acknowledgment of working-class women’s rights in the public domain.