The unpublished archives of the participants of the Second Russian (Students’) Expedition to South America in 1914-1915 contain interesting observations on the life of urban and rural population. The travelers met emigrants from the Russian Empire all along their way. Their letters and diaries describe typical situations from the life of emigrants and reflect the roles of Jews in the development of the South American continent (Argentina, Paraguay and Chile). The letters of recommendation issued by local intellectuals for the young scientists allow us to study the communication system and connections in the emigrant communities. Notes by S. V. Geiman contain valuable information about the circles of local intelligentsia and some significant figures of East European descent, primarily Jews. The families of Pavlovsky, Marienhoff and other educated emigrants from Russia played an important role in the economic development of Argentina. The family of the Swiss zoologist M. Bertoni set up a scientific laboratory i