Just as states claimed a monopoly on the legitimate use of violence, modern states claimed exclusive authority to authorize and regulate movement across and within their borders. Individuals lost the freedom to move as a private right and became dependent on states for documents that grant permission to travel.
Identity papers do not merely restrict people; they 'embrace' them, binding individuals to particular states that claim them as members and resources. This administrative grip makes populations legible and available for taxation, conscription, policing, and welfare, so documentation is a form of penetration into society, not only a barrier at the edge.
Passports and identity papers do not passively reflect pre-existing identities but actively create the categories (national, alien, citizen) by which people are known and governed. The capacity to reliably attach an identity to a person is itself a historical achievement states had to build through registries, standardized formats, and bureaucratic infrastructure.
Revolutionary France oscillated sharply: passport controls were denounced as despotic affronts to the freedom of movement, yet repeatedly reinstated to track suspect persons, emigres, and vagrants. This shows that even regimes founded on liberty found internal and external movement controls too useful for security and order to abandon.
Authority to document and authorize movement shifted upward from municipalities, parishes, and private actors to the central national state over the nineteenth and twentieth centuries. This centralization was uneven and contested, but it concentrated in national governments the power to define who belongs and who may enter or leave.
Reading control over movement through documents reveals that a border operates wherever papers are demanded, not only at a geographic line. The ability to filter people depends less on walls than on systems of registration and credentials that distinguish the authorized from the unauthorized.