Human mobility has always been a pre-condition for human development, yet few issues today remain subject to such elaborate legal restrictions. The Schengen acquis is exemplary of this as a composite network of legalities that extend over a broad range of human activities. This paper pioneers legal infrastructures as an analytical tool to bring into focus law's fundamental role in shaping human (im)mobility. Part I sets the theoretical frame by conceptualizing Schengen as a legal infrastructure through a brief tour through the scholarly field of infrastructural studies. Part II then traces the emergence of the Schengen legal infrastructure through historical iterations of physicality, accretion, and entanglement. Part III further shows how Schengen has transformed to actively mediate human mobility and normative frameworks also outside the European space. Part IV concludes briefly on the implications of our analysis for understanding Schengen as a cornerstone of European mobility law.