Nationality is the most important legal mechanism for sorting and classifying the world's population today. An individual's state of birth or naturalization determines where he or she can and cannot be and what he or she can and cannot do. Although this system may appear universal, even natural, Will Hanley shows it arose just a century ago. He uses the multinational Mediterranean city of Alexandria to trace a genealogy of the nation and the formation of the modern subject. Alexandria in 1880 was an immigrant boomtown ruled by dozens of overlapping regimes. On its streets and in its police stations and courtrooms, people were identified according to name, occupation, place of origin, sect, physical description, and other attributes. By 1914, nationality had become the leading category of identification. Even before nationalist claims for independence and decolonization were widespread, nationality laws governed Alexandria's population. Identifying with Nationality traces the advent of modern national citizenships to multinational, transimperial settings such as turn-of-the-century colonial Alexandria. Ordinary individuals abandoned old identifiers and grasped nationality as the best means to access the protections promised by expanding states, creating a problematic system that continues to complicate rules of status, mobility, and residency.