In 2000, the AFL-CIO officially embraced the call for amnesty for undocumented immigrant workers, reversing long-standing policy in favor of greater restriction and border enforcement. The roots of this new approach stretched back to the 1970s, when the growing presence of undocumented workers in the industrial workforce challenged organized labor's nationalist orthodoxy. Taking the International Ladies Garment Workers Union (ILGWU) in Los Angeles as a case study, we show how one union confronted new demographic and organizing realities and recognized the demand for unionization among new immigrants. Radical community organizers, legal advocates, and union organizing staff created a practice of labor citizenship, the recognition of the immigrants’ right to remain by virtue the demand for their labor. The promise of belonging through organizing and collective bargaining was limited by state power and the structural weakness of organized labor in the emerging neoliberal economy. Nevertheless, ILGWU campaigns trained a cohort of organizers that would become central to the union upsurge in Los Angeles during the 1990s.