The article analyses the scientific works of Afanasy Prokopievich Shchapov (3.10.1831-25.02.1876) and his contribution to the national scholarship of the 1850s. Despite extensive literature on the issue, its source studies aspect remains untouched upon. For instance, documents of the file “On professor A. P. Shchapov in the State Archive of the Russian Federation” (1861– 64) were used selectively, out of the context, without analyzing the source features. The source-based approach involves, in addition to using the document in research, studying the collection as a whole. Taking into account the interdependence of documents in the file, the departmental and specific context of their origin expands the possibilities of establishing the degree of the source reliability. The article is to analyze the representativeness of the documents "On professor A. P. Shchapov in the State Archive of the Russian Federation" (1861–64).” It is based on studying the origin and content of the collection, its structure, internal connections and on comparison of individual documents and the “package.” The study has showed that the “file” as a “part of the past” objectively reflects content, forms, and methods of work of the ministries and departments, the role of the emperor in the decision-making. The materials of the dossier are the carriers of genuine clerical paraphernalia, facts of real activities of the departments, and plans of the Democrats in the 1860s. The social function of the “head” department, its ideological dominant determines the composition of the file. It includes sources of personal provenance, historical research of the scientist, and record management materials. They contain data on the life of the historian from February 1861 to March 1864. Each department aimed to obtain objective information, used document forms endorsed by personal signature of the minister. The materials are linked chronologically and thematically. The bureaucratic interest in accurate information and the inter-document context, as well as the direct comparison of documents testify to their reliability. The file of professor Shchapov, due to the specifics of the “ministerial” selection of documents, could not capture the history of Shchapov’s life and work in Kazan and St. Petersburg in 1861–64 in its entirety, but it preserved some unique elements of his biography.