By 1750, vaccinations, based on the method introduced by Onesimus, would be standard practice in Massachusetts and later in the rest of the country. “What is clear is that the knowledge he passed on saved hundreds of lives—and led to the eventual eradication of smallpox,” wrote the author Erin Blakemore. “It remains the only infectious disease to have been entirely wiped out.” For his contribution to science, Onesimus does not appear even to have fully won his freedom.
