Migrant Connections is a digital research infrastructure for historical research on German migration to the United States in the 19th and 20th centuries. Its aim is to foster research on mobility, spaces of knowledge production, and transatlantic communication systems. The platform focuses on the integration and linking of different digital theories and methods for developing, linking, analyzing, and publishing large amounts of historical data to enable different methodologies for reading and interpreting sources. “Migrant Connections” brings together collections from the United States, Germany, and elsewhere representing a broad array of materials, from letters and diaries to poems and news articles. By including different sources of, by, and about multiple categories of actors—emigrants and those who stayed at home, whether categorized by gender, age, religious denomination, or social class—the platform’s objective is to use hidden and neglected sources to gain new insights into relational perspectives and explore how people from different social, religious, or ethnic backgrounds experienced migration-related social, political, or economic challenges.