This paper seeks to understand how US labor unions - once key institutions in American political and economic life - can re-emerge as important and viable organizations. Building on the extensive literature on the "social embeddedness" of economic activity as well as on union revitalization, we hypothesize that where local unions are able to rebuild linkages to other local groups, they should be successful at revitalizing themselves organizationally. Where unions fail to embed themselves in their broader communities - notwithstanding genuine efforts at launching new strategies and rebuilding their own organizations - they are likely to stagnate. The paper reports the results of two matched pair case studies of building trade locals in Boston, Massachusetts, and Portland, Oregon. One set of cases focuses on Pipetrades in the two cities. The other set ofcases focuses on the cities' Carpenters unions. To gain more objective information on the unions' embeddedness in local networks we employed a survey that identified approximately 100 industry stakeholder organizations including builders, architects, engineers, major property owners, neighborhood and environmental groups, local and state governments, and banks and lenders. We received responses from 46% of the organizations we contacted from which we were able to conduct a series of network analyses that complement our qualitative research Includes bibliographical references (leaves 33-35) This paper seeks to understand how US labor unions - once key institutions in American political and economic life - can re-emerge as important and viable organizations. Building on the extensive literature on the "social embeddedness" of economic activity as well as on union revitalization, we hypothesize that where local unions are able to rebuild linkages to other local groups, they should be successful at revitalizing themselves organizationally. Where unions fail to embed themselves in their broader communities - notwithstanding genuine efforts at launching new strategies and rebuilding their own organizations - they are likely to stagnate. The paper reports the results of two matched pair case studies of building trade locals in Boston, Massachusetts, and Portland, Oregon. One set of cases focuses on Pipetrades in the two cities. The other set ofcases focuses on the cities' Carpenters unions. To gain more objective information on the unions' embeddedness in local networks we employed a survey that identified approximately 100 industry stakeholder organizations including builders, architects, engineers, major property owners, neighborhood and environmental groups, local and state governments, and banks and lenders. We received responses from 46% of the organizations we contacted from which we were able to conduct a series of network analyses that complement our qualitative research