From Empire to Humanity: The American Revolution and the Origins of Humanitarianism tells the story of a generation of American and British activists who transformed humanitarianism as they adjusted to being foreigners in the wake of the American Revolution. In the decades before the Revolution, Americans and Britons shared an imperial approach to charitable activity. Growing up in the increasingly integrated British Atlantic world, future activists from the British Isles, North America, and the Caribbean developed expansive outlooks and connections. For budding doctors, this was especially true. American independence put an end their common imperial humanitarianism but not their transatlantic ties, their far-reaching visions, or their belief that philanthropy was a tool of statecraft and reconciliation. In the postwar years, with doctor-activists at the forefront, they collaborated in medical philanthropy, antislavery, prison reform, poor relief, educational charities, and more. The nature of their cooperation, however, had changed. No longer members of the same polity, the erstwhile compatriots adopted a universal approach to their beneficence as they reimagined bonds with people who were now legal strangers. The basis of renewed cooperation, universal benevolence could also be a source of tension. With the new wars at the end of the century, activists optimistic cosmopolitanism waned while their practices endured.