The earliest documented use of the smallpox virus being used as a biological weapon was during the French and Indian Wars of 1754-67. British soldiers fighting in North America at that time distributed blankets that had been contaminated with smallpox amongst the native American Indians. Epidemics followed, killing more than 50% of the affected tribes. Smallpox is extremely lethal to populations that are not vaccinated against it. Death usually occurs within 2 weeks. Historians suspect, however, that the Spanish conquistador Francisco Pizarro gave contaminated clothing to South American natives in the fifteenth century. see rarest disease.
