It is certainly interesting that, as Joseph Ellis noted, historians have only recently “recognized that the American Revolution occurred within a virulent smallpox epidemic of continental scope that claimed about 100,000 lives.” I think Elizabeth Fenn exuded an extraordinary amount of modesty when she discussed stumbling upon bits and pieces of a story that had not been told in its entirety, a story that was indeed “something big,” and which she finally brought to light more than two centuries after the events in question.
Smallpox was an Old World disease, so the majority of British soldiers possessed a natural immunity to the disease. American colonists, on the other hand, had spent enough generations on this side of the Atlantic that any inherent immunity their immigrant ancestors may have had was long gone. American Indians were particularly susceptible to the ravages of the disease, since their collective exposure to smallpox had only begun in the recent past. Other factors, such as malnourishment, Native American medicinal practices, and genetic predispositions, may have contributed to the enormous and widespread lethality of smallpox among the indigenous population.
Any battlefield makes an excellent breeding ground for diseases of all kinds, and the battlefields of the American Revolution were no different. Large groups of soldiers and civilian refugees were perfect vectors for the spread of smallpox, and the often unsanitary conditions of army and refugee camps only exacerbated the problem of disease transmission. Washington, who had survived smallpox as a young man in the Caribbean, recognized the problem early on during the siege of Boston, and although a relatively primitive inoculation process was available, he was faced with a “thorny dilemma.” If virulent smallpox gained a foothold in his largely unexposed Continental army, it could have a devastating impact. On the other hand, inoculating his troops posed a host of problems as well. If the soldiers were inoculated a few at a time, the virus had a good chance of spiraling into a full-blown epidemic; if Washington chose to inoculate his entire army all at once, the British might be enticed to attack the stricken camp. In the end, Washington did begin a program of inoculation for his Continental soldiers, but it was two years before the inoculations became mandatory.
It is very odd to me that Fenn was the first to put this story together, that it took so long for historians to figure out the enormous part smallpox played in the American Revolution. Diseases have always been a problem during war, though modern medicine has been able to limit the impact in many ways. (As a twenty-first century soldier in Afghanistan, I was required to take anti-malaria medication and treat my uniforms with mosquito repellant.) Given the sheer number and variety of sources referenced by Fenn, it is astounding that earlier historians did not recognize the breadth and scope of smallpox during the Revolution. Perhaps the romantic national mythology of our nation’s founding simply did not have room for the horrifyingly mundane realities of death by disease. A group of brave patriots facing death on Breed’s Hill was far more stirring than a group of their comrades dying of smallpox in a squalid field hospital. Or maybe the fact that many of the wealthier colonists were able to afford the fairly expensive inoculation had something to do with the story’s relegation to the footnotes of history. By the end of the first year of the war, most of the Continental army was composed of the lowest classes of society; the story of their death, either by musket ball or by smallpox, was not as important as the story of Alexander Hamilton charging the redoubt at Yorktown.
 Joseph J. Ellis, His Excellency: George Washington (New York: Vintage Books, 2004), 86.
 Elizabeth A. Fenn, Pox Americana: The Great Smallpox Epidemic of 1775-82 (New York: Hill and Wang, 2001), x.
 Ibid., 27-28; Ellis, His Excellency, 86.
 Fenn, Pox Americana, 24-27.
 Ibid., 47.
 Ellis, His Excellency, 87.