In the early Victorian age, the streets of East London were home to migrants from different regions and religions. In the midst of this area lay the famous Rag Fair street market, sustained by trade routes stretching across the globe. The market’s history demonstrates that it was not only a place of economic exchange, but also an intercultural contact zone where Jewish and Irish migrants mingled, entered client relationships and forged political alliances. Reconstructing the varied (partly multiethnic) group-building processes operating in the market, Rag Fair draws on approaches across migration history, economic history, economic anthropology and the sociology of political movements to uncover the social mechanisms at work in the old clothing trade.