Study of the unemployed workers' movement in Tartagal and Mosconi, Argentina, shows significant continuities between the piquetero organizations there and the militant unions of the past. In the new context characterized by massive unemployment, leaders who had left-wing union or political experience led and developed protest movements that can be framed in terms of capital-labor conflict. Grassroots activists without previous experience in organizing collective action learned from their participation in the struggle. [Reprinted by permission of Sage Publications Inc., copyright holder.]