Prevailing conceptions of organizational embeddedness emphasize linkages to exchange partners via elites and contracts. What is neglected, the authors argue, is the nature and potential impact from the voluntary associations of rank-and-file members with the panoply of organizations in their daily lives, including churches, PTAs, and sports teams. The functions of these organizations provide contexts in which individuals trade information and form opinions about organizations and their members. By participating, individuals embed their own organizations in a broader organizational culture. This article treats the embeddedness of unions in the interorganizational network as a factor that has impacted and varied with the decline of organized labor Organizational affiliation networks containing 18,263 individuals, drawn from the 1974-1994 General Social Survey data, show the isolation of unions in American organizational culture despite their relatively high rates of membership. Chronic aspects of the problem include union members' lack of nonunion voluntary association membership in general and the particularly low embeddedness of the organizations with which they affiliate.