This article examines immigrant banking in the United States as a pervasive, cross-ethnic development from its heyday during the 1880s and 1890s through its gradual decline, beginning around 1907, until the mid-1920s. Unlike traditional bankers, immigrant bankers usually operated out of other commercial enterprises, such as groceries, bakeries, saloons, booksellers, boarding houses, and pedlars' carts. Located within the economic and social fabric of immigrant neighbourhoods, these ethnic entrepreneurs were crucial financial intermediaries for new immigrants, most notably eastern and southern European immigrants, and they eventually became important investors and property holders in developing urban ethnic enclaves within American cities. As they flourished, however, operators of mainstream banks looked to expand their own business into immigrant communities. By increasing their own services and exploiting growing fears of immigrants and loan sharks, opponents of immigrant bankers passed laws that spelled the end to this important form of popular banking in the early twentieth century.