The League of Nations Search Engine (LONSEA). Available at: http://lonsea.org/; The data on "intellectual cooperation" from Dr. Martin Grandjean Github page. Available at: https://github.com/grandjeanmartin/intellectual-cooperation; WikiData. Available at: https://www.wikidata.org/, The present dataset contains (meta) information extracted from the materials preserved in the archives of the International Institute of Intellectual Cooperation (IIIC) kept at the UNESCO headquarters in Paris, which are available online at [https://atom.archives.unesco.org/iiic ]. More precisely, the dataset focuses on subseries A and F from the Series Correspondence. Using machine learning and natural language processing (NLP) techniques, we have parsed scanned documents and extracted from them meta-information like: people and location mentions, language (e.g., French), typology of the explored material (e.g., letter vs. attached document), material medium (e.g., handwritten vs. typewritten), and -- if possible -- its year of drafting. Moreover, we have associated these entities (e.g., a given person) and information to the specific document(s) where they appear. We have divided the dataset in three files: one focused on people and two on locations (one for countries and another for cities). This dataset has been generated within the ERC-StG project named "Social Networks of the Past: Mapping Hispanic and Lusophone Literary Modernity, 1898-1959" led by Diana Roig-Sanz., European Research Council (ERC): 803860, Peer reviewed