This paper publishes 735,000 historical passenger entries from the German North Sea port of Bremen, created between 1830 and 1939, and now structured, enriched, and processed into a research-ready database. It provides an overview of the original archival documents and their datafication, beginning with a historical account of why the passenger lists were created and which information they recorded. Building on extensive prior work—largely carried out by family researchers—the lists were transcribed manually and first made available online in 2003. To enhance their analytical value, we computationally post-processed these data through: (1) data cleaning, especially addressing spelling variants and transcription errors; (2) data normalisation, including conversion into standardised formats; and (3) data augmentation by adding identifiers, geographic information, and multiple classifications. Finally, we discuss limitations of the resulting dataset as well as its analytical potential.