This article investigates the problem of ethnic boundary making in a changing context. Our case is Boston’s North End, a historically Italian neighborhood undergoing changes to its social and physical environment, making the ethnic definition of neighborhood identity and belonging more difficult though not less salient. Consequently, participants in the workings of the neighborhood—residents, business owners, politicians—face challenges of both boundary placement (who is Italian and who is not?), as well as cultural content (what does it mean to be “Italian”?). Rather than viewing Italian ethnicity as simply weakening over time, we argue that the North End shows ethnicity is in a stage of category divergence, where the still-dominant ethnic identity is juxtaposed not against another ethnic out-group, but at various times against boundaries of class and race, commercial and community values, even city political boundaries. Drawing on ethnographic research and in-depth interviews, we describe three group identity frames that illustrate these processes and reveal how Italian ethnicity continues to animate discourse and action in the neighborhood.