Washington’s Victory over Smallpox

Throughout the eighteenth century, smallpox was a dreaded disease in the colonies, often appearing in epidemics that ravaged entire communities, with mortalities ranging from 15 to 50%.1 There were only two ways to prevent an outbreak of the extremely contagious Variola virus—either through isolation via quarantine or inoculation.1 In inoculation, the patient was deliberately exposed to the virus, becoming contagious after approximately 12 days and remaining so for another 2 weeks. Although the procedure had a milder infection,1 it still had an approximate 2% mortality risk.2 Inoculation was also an expensive, grueling, and time-consuming process that was too impractical for the poor.2 Many colonists refused the procedure, and it was outright banned in a number of states.1 With the outbreak of the American Revolution, General George Washington was highly restricted in dealing with smallpox—he had to request the permission of local authorities to inoculate his troops, and even setting up hospitals to quarantine infected soldiers required local permission.1 Washington was intimately familiar with the disease, having personally contracted smallpox at the age of 19 years.3 On a strategic level, effective management of infectious disease also played a major role in contemporary warfare—approximately 90% of the Continental Army’s 70,000 fatalities from 1775 to1781 were because of the disease.4 Despite his concerns about the health of his soldiers, Washington was forced to acquiesce in the early stages of the war, and in 1776 ordered, “No person whatever, belonging to the Army, is to be inoculated for the smallpox.”5 Established on May 31, 1775, the Continental Army soon saw action at the Battle of Bunker Hill, followed by a prolonged siege of British forces trapped within Boston.5 Smallpox soon broke out within the besieged city. Unlike their American counterparts, the majority of the British soldiers were already immune,2 because of the endemic nature of smallpox in Europe versus its epidemic nature in North America.1 The Boston garrison quickly instituted a program of voluntary inoculation for their troops and quarantined any soldiers who refused to participate, which further mitigated the impact of the outbreak.1 The besieging Continental Army also had low rates of disease because of limited combat, a sympathetic populace, good lines of supply, and Washington’s personal interest in proper camp sanitation.6 Despite persistent rumors of British attempts to deliberately spread the disease to American forces, the Continental Army experienced no significant outbreaks, further aided by Washington’s strict quarantine policy.1 However, the threat of the smallpox outbreak in Boston played a significant role in Washington’s planning. Already limited in manpower and supplies, Washington was reluctant to expose his troops to smallpox through an outright assault. When the British finally abandoned the city in March 1776, Washington ordered that the occupation force only include men who had already had the disease.1 The mere threat of the disease against his largely unimmune troops played a major role in Washington’s military decisions during the early stages of the war.1 In contrast to the relatively benign siege of Boston, smallpox ravaged the disastrous American attempt to secure Canada. Just a few months after the start of the invasion in August 1775, the American army had been reduced to a mere shadow of its former strength as a result of rampant smallpox outbreaks. One general noted “… that infernal disorder, the small-pox, has ruined our army…”1 and John Adams wrote in 1776 that “… the small-pox is ten times more terrible than Britons, Canadians, and Indians together.”1 Not only did the smallpox kill and incapacitate soldiers, but it led to rampart desertions; most of the invading army’s enlistments expired on January 1, 1776, and fear of smallpox led the majority of soldiers to forfeit any re-enlistment. Reinforcements became ever more difficult to obtain, as fear of smallpox greatly impeded recruitment efforts across the former colonies.2 Limited on men, supplies, and time, General Richard Montgomery was forced into a disastrous and ill-planned assault on Montreal on December 30 to 31, 1775 that led to his death, hundreds of Americans being captured, and a crippling retreat from the region.1 It was not until General Horatio Gates took command of the broken army at Ticonderoga and stabilized the army’s health through quarantine, sanitary standards, and the inoculation of reinforcements that the situation could be stabilized and Washington’s northern flank protected.6 By then, the American force had lost 5,500 soldiers to smallpox out of an original force of 10,000.7 Throughout the Northern Campaign, many American soldiers haphazardly attempted to self-inoculate. However, without proper quarantine procedures, this only further spread the disease and, given the high level of care and prolonged convalescence from inoculation, removed even more soldiers from the field at a critical juncture in the war.1 The situation grew so dire that General Benedict Arnold issued orders making the procedure punishable by death and desperately requested reinforcements that had already been inoculated.1 However, this did nothing to stop the rampant spread of the disease. Ultimately, despite high hopes in the Continental Congress, the Northern Campaign ended in defeat; Canada would remain in British hands.1 The American failure in Canada, as well as growing numbers of smallpox within his army in early 1777, posed a significant threat to the health of Washington’s troops.2 Further exacerbating the issue were persistent American fears that the British were using biological warfare—first through attempts to spread smallpox during the siege of Boston1 and then through rumors that Canadian forces were sending smallpox victims to infect the American invaders.1 A thorough analysis of these accusations is outside the limit of this paper, but British forces did have a history of employing smallpox as an offensive weapon during the earlier Seven Year’s War.2 Given this, Washington decided upon a program of mass inoculation for his army—the first military program of mandatory smallpox inoculation in the world, as British forces practiced voluntary inoculation.7 This posed a significant military risk because of the large numbers of incapacitated soldiers convalescing from the procedure, the risk of uncontrolled infection, and the amount of secrecy required for such an operation.2 In preparation for the summer campaign, Continental soldiers were inoculated at major sites across the colonies from February to May 1777. Divisions were inoculated at 5- to 6-day intervals and placed under guard in isolation and treatment chambers.1 To maximize efficiency, Washington also introduced a program of inoculating recruits immediately upon joining the army.1 The program of mass inoculation, combined with rigorous quarantine of infected soldiers, proved successful. By 1777, recruitment numbers vastly increased as smallpox posed less of a threat to potential recruits; by 1779 to 1780, smallpox ceased to be a major concern for American forces.1 In contrast, British forces became more vulnerable to smallpox as the war dragged on, largely because of recruitment of native-born Americans. The loss of such a key advantage played a significant role in the later stages of the war.2 Smallpox played a pivotal role in the early American Revolution, limiting Washington’s strategic options during the siege of Boston and contributing to the destruction of the American foray into Canada. However, Washington’s decision to introduce mass inoculation of his troops reversed the tide of this disease and played a key role in securing ultimate victory. Given long-standing American fears about the procedure, it is highly unlikely that any other contemporary figure could have achieved such a drastic change in inoculation policy. Washington’s determination ultimately made the “single greatest contribution to preventive medicine during the war.”6 The authors have no acknowledgements. None declared. None declared. Not applicable. Not applicable. Not applicable. None declared. CPT M.D.T. conceived of the article, performed initial research, and wrote the initial draft of the article. COL J.S. provided revisions and suggestions for subsequent drafts. Both authors approved the final manuscript.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.