This article analyzes and demonstrates the declining social selectivity of migration distance in Europe’s long nineteenth century and argues that this drove a radically new process of democratization of long-distance migration. It uses innovative spatial and quantitative analysis of nominal data on more than 5,000 international migrants who moved to the booming port city of Antwerp in present-day Belgium between 1850 and 1910. Examining the changes in migrants’ origins and trajectories on the one hand, and in their profiles in terms of gender and occupations on the other hand, it argues that the main evolutions observed represent an overall loosening of the ancien régime link between migration distance on the one hand and social selectivity on the other hand. By focusing on gender and social class as markers of social selectivity and by mapping the impressive expansion of the trajectories of Antwerp’s growing number of long-distance migrants, it lays bare the spatial, gender, and social dimensions that contributed to a general process of democratization of long-distance migration. As such, it sheds new light on the dynamics of Europe’s so-called “mobility transition” in the long nineteenth century.