We are editing 19th century migrant letters that are physically located in German and American archives. In order to be able to reconstruct migration patterns and migrant networks, we would like to mark persons with a unique identifier. Since these are “ordinary people”, we do not find them in existing Authority Files such as GND, LoC or Wikidata. How should we reference the existing biographical information and which markup language should we use so that the biographical information that we retrieve from the letters and from archives can easily be enhanced by future biographical research? Should we transfer our data into the Integrated Authority File (GND) and if yes, how can we do this? Secondly, we would like to store and document all biographical details (baptism, marriage and death records, census records, pension records, emigration records, ship lists) as well as additional information gathered from the letters such as occupation, places of living and family events, contacts between migrants, their families, old and new neighbors, friends and acquaintances, in order to map and visualize the migration and mobility networks. Which service and platform should we use for cooperative research data management and the long-term preservation of our research data? Which digital tools should we use for GIS mapping and network visualization?