We apply innovative digital methods for data linkage and analysis to gain historical insight into a topic that is currently hotly debated in both the political and public arena: what is the economic contribution of migrant workers on a recipient economy? We present preliminary results from ongoing research into the eighteenth-century Dutch maritime sector. This was a key sector of the economy, characterised by a high level of migrant participation and well-known today for leaving rich sources. Our approach to uncover the link between migration and economic advancement centres on two aspects of what is generally referred to as job mobility: promotion and job switching. By identifying those individuals that during their careers experienced promotion and/or job switching we lay bare the extent to which human capital levels of migrants and native workers differed, and seek to explain what caused the differences.