For a century, the Lazaretto quarantine station on the Delaware River protected Philadelphia against imported epidemics. The oldest surviving quarantine facility in the Western Hemisphere holds within its walls countless stories of illness and death, immigration and survival, and politics and fear. My project, in conjunction with parallel historic preservation and public history campaigns, aims to recover these stories and reinsert them into our collective historical memory at a time when immigration, homeland security, and pandemic preparedness once again fill the daily headlines. Working with other scholars wrestling with questions of marginality, isolation, and exclusion, I will interrogate the theory, the practice, and the experience of quarantine as windows on the tensions and struggles through which a rapidly growing nation built and protected itself.