Using an unusual case of a democratic and militant shipbuilding union in 1960s South Korea as a window on society, this article explores the politics and ethos of the first decade of Park Chung Hee's rule. Pronounced public support for the union in the region, dense links between the unionists and local progressives, and the surprisingly optimistic and positive expectations of the military government that shipyard workers exhibited in this period all call our attention to the still quite fluid and open terrain of politics before the full-blown authoritarianism of the 1970s. These dynamic aspects of the 1960s, when both elites and non-elites engaged major postcolonial questions of democracy, development, and unification, are mostly hidden from view today, overwhelmed by the power of the dominant minju discourse that became hegemonic in the democracy movement during the 1980s and 1990s. Excavating the forgotten alliance between an important union and the progressives surrounding it thus opens a space for alternative understandings of South Korean development and democratization.