This article analyzes integrative dynamics within civil society by looking at civic networks — the web of collaborative ties between participatory associations acting on behalf of public and collective interests. Drawing upon evidence from Glasgow and Bristol, we identify a polycentric model of civic coordination based on horizontal solidarity, in which associations form dense clusters of strong, identity ties (‘social bonds’), bridged by fewer, instrumental ties (‘transactions’). Basic relational mechanisms, consistent across localities, provide the basis for both micro and macro integration: they generate networks tight enough to embed civic associations in a distinctive environment, but open enough to connect them to a broader range of civic organizations. While contributing primarily to our understanding of political networks, our findings also have implication for current debates on associational social capital and the impact of political contexts on the structure of collective action. © 2007 by The University of Chicago. All rights reserved.