This collection consists of materials gathered by Simon Dubnow, an influential political thinker, educator, writer, activist, and preeminent historian of Russian Jewry. The materials reflect central subjects of his historical research, such as communal organization, persecutions, and Hasidism, as well as pressing issues of his time, most significantly pogroms and the question of Jewish emancipation. Much of the material comprises information meticulously copied and sent to Dubnow by individuals throughout the Russian Empire for the purpose of aiding his research. The collection demonstrates Dubnow's importance in helping to establish the idea of Jewish ethnographic history.