I. A. Vinogradov, a local historian, archaeologist, museum and archival worker, occupies a worthy place among the remarkable galaxy of Tver local historians of the late XIX – first third of the XX century. Despite his wide fame at the time, information about him remained concise and did not reveal his multifaceted and long-term activities in the field of Tver local lore, archeology, museum and archival construction. The known materials about him are not numerous, besides they are stored in different places. The letters introduced into scientific circulation addressed to S. F. Platonov, who had 30 years of fruitful ties with Tver local historians, make it possible to fill many gaps in the professional and social life of a remarkable person. This correspondence is the last significant link of communication between the metropolitan professor and Tver history lovers and allows us to complete the picture of the life of the scientific and local history institutions of the Tver Region, the Tver Provincial Scientific Archival Commission and the local museum. The letters are a valuable source about the events that took place on the initiative of the Tver PSAC and S. F. Platonov’s participation in them.