Chapter 11 discusses the early vaccination in North America. Dr Benjamin Waterhouse pioneered the practice in Boston in August 1800, rebranded cowpox as kinepox and briefly enjoyed a monopoly of the practice. Aware of the hazards associated with smallpox inoculation, Americans welcomed the new prophylaxis. President Thomson Jefferson took up the lancet at Monticello and, largely in a private capacity, helped to entrench and extend the practice. Philadelphia emerged as a new hub of vaccination, seeding its establishment in the southern states and on the western frontier. Serviceable to individuals and communities, the new practice served to bind together the new nation, with slaves often among the first to be vaccinated and prophylaxis being offered, as opportunities arose, to Native Americans. The problem of maintaining a supply of good vaccine in sparsely populated districts and on the frontier appeared more urgent with the outbreak of war with Britain in 1812 and explains the Federal government’s unusual decision to fund a (short-lived) National Vaccine Agency in Baltimore.