Jean-Emmanuel Gilibert (1741-1814) has been the subject of few biographical works. This paper presents the results of research from unpublished documents, unknown by historians until now. The information, publishedin old sources as in Gilibert autobiographical sketches or in catalogues of natural history papers auctions, is critically analyzed here. We also tried to establish a list of documents from those cited by Gilibert biographers, but lost today. The author both presents and comments letters to Antoine-Laurent de Jussieu (1748-1836) and André Thouin (1747-1824), as well as a letter to an unknown receiver, in the autograph's collection of Gustave Thuret (1747-1824) and Eduard Bornet (1828-1911)--which is conserved in the collection of the National Museum of Natural History in Paris. Precious information about Gilibert and his stay in Lithuania was found in the letters of Antoine Gouan (1733-1821) to Philippe-Isidore Picot de Lapeyrouse (1744-1818). Research were also conducted in the Museum's herbarium in order to find Gilibert's specimens from Lithuania as well as to discover more information about the naturalist himself. The documents of Jean Hermann (1738-1800) linked with Gilibert were found in Strasbourg's National and University Libraries and in the Municipal Archives; a letter from Gilibert to Antoine-Laurent de Jussieu was also discovered in this collection. Some new and interesting data came from a register of Hermann's natural history cabinet visitors Some additional information about Gilibert's life and work was obtained as a result of the analysis of manuscripts conserved in the National Academy of Medicine in Paris, more specifically in Gilibert's correspondences from Lithuania and Lyon about illnesses and epidemics. The information obtained allowed a better knowledge of the history of Gilibert floristic works in Lithuania, his zoological research, his practice of medicine and his study of different pathologies, his way of collecting and the collection itself of natural history specimens and the history of Gouan's herbarium and Pierre Richer de Belleval's copper plates brought from France to Lithuania. Some facts about Gilibert's life unknown to his biographers were also discovered in these manuscripts. We also tried to discover to what extent the information obtained in Lithuania was used by Gilibert in France. The role of Gilibert in the description of the Alps flora and his participation in the work of Dominique Villars (1745-1814) were discussed. We tried to estimate the impact of Gilibert's experience in Lithuania on his bio-geographical conceptions, as well as on botany in the XIX century. Based on this information, the character of Gilibert was found to be representative of a typical member of the "république des savants" while still remaining very specific to his atypical life. We therefore also tried to understand to what extent Gilibert was a typical naturalist of the XVIII century.