In 1775, Lord Dunmore, the royal governor of Virginia, offered freedom to any African American who fought for the British cause against the colonial rebels in his province. Dunmore's plan to reconquer Virginia with his “Ethiopian Regiment” ended in failure, not due to a lack of willing volunteers but because of a familiar eighteenth-century killer: smallpox. Five years later, similar proclamations were issued in South Carolina. Yet smallpox again hindered British designs, devastating the eager African Americans who flooded to their lines. This paper uses primary source material and research on smallpox to analyze the experiences of African Americans who actively sought freedom with the British during the Revolutionary War. Focussing on the differing regions of Virginia and South Carolina this paper will assess the impact of smallpox on British military designs for runaway slaves while also evaluating the reasons why the disease had such a devastating effect on African Americans during the period. Overall, this paper will show how smallpox, so common in eighteenth-century Europe, put a fatal end to the first widespread push for emancipation on the American continent and helped derail one of Britain's best hopes for turning the tide in the Revolutionary War.