Book excerpt: The mass migration of East European Jews and their resettlement in cities throughout Europe, the United States, Argentina, the Middle East and Australia in the late 19th and early 20th centuries not only transformed the demographic and cultural centers of world Jewry, it also reshaped Jews' understanding and performance of their diasporic identities. Rebecca Kobrin's study of the dispersal of Jews from one city in Poland -- Bialystok -- demonstrates how the act of migration set in motion a wide range of transformations that led the migrants to imagine themselves as exiles not only from the mythic Land of Israel but most immediately from their east European homeland. Kobrin explores the organizations, institutions, newspapers, and philanthropies that the Bialystokers created around the world and that reshaped their perceptions of exile and diaspora.