The containment of immigrants along the US/Mexico border illuminates the complex spatial implications associated with the securitization of migration enforcement. The production of marginalized, carceral national spaces has particular consequences for the people who inhabit them, as processes of spatial illegality shape their daily lives. Our analyses draw on five years of ethnographic study in the Rio Grande Valley of Texas. Here, we focus on the experiences of sixty‐one undocumented youth, including recipients of Deferred Action for Childhood Arrivals, to explore how the spatial violence created by checkpoints and everyday policing practices lead to experiences of confinement and accelerate processes of social exclusion. Spillover effects occur as all inhabitants must pass through inspection points and demonstrate proof of identity and legal residency; this contributes to the reformulation of citizenship. To this, our article adds insight into how social membership is experienced at the checkpoints so that “citizenship” and “authorization” become conflated. Early childhood and youth experiences of freely crossing spaces with school programs yet living with uncertain and precarious status contribute to persistent fear, instability, and confusion under a multilayered immigration policy regime.