Smallpox--the most devastating disease in human history--struck the American colonies in 1773. Andrew Wehrman (Central Michigan University) joins us to talk about the political responses to the disease, in Marblehead and Salem, Massachusetts, and Norfolk, Virginia, and what Americans learned about the contagion and how to combat it, as he discusses in his new book, Contagion of Liberty: The Politics of Smallpox in the American Revolution.