One Man’s Campaign against Smallpox: James Thacher, M.D., Continental Army Physician

James Thacher. (New York Public Library)

James Thacher’s contribution to the history of smallpox and to the Revolutionary War has not been fully appreciated. In the historical scholarship, his tireless efforts against the disease have been acknowledged but only in passing.[1] Under extremely trying conditions, Thacher and his colleagues cared for those stricken with the virus and inoculated both combatants and civilians against it.

Eventually, in his 1823 Military Journal, Thacher recorded his clinical experiences with smallpox. A continuous eye-witness account, this text established his reputation as an historian of the American War.[2] Several entries describe how outbreaks constituted strategic and health emergencies. When entering Boston, on March 22, 1776, after the British evacuation, Thacher recalled the “friendly solicitude” of the people as they greeted Washington’s army upon its return; but the lingering presence of smallpox dampened the sense of relief. Many could not visit their newly-liberated friends because of it.[3] Moreover, in the spring of that year, efforts to contain the disease through quarantine and isolation proved unsuccessful. Wholesale inoculation appeared to be the only way of preventing a crippling outbreak in the ranks which would have imperiled the war effort. At the outset, Thacher and all authorized inoculators had to be immunized before they could treat the soldiers and residents of Boston. This had to be done to prevent them from contracting the pox themselves and from spreading it to patients. Earlier, Washington had proscribed immunization because he was justifiably concerned that the procedure, which utilized infectious scabs and exudate, risked infecting those who did not develop immunity. His greatest concern was that the inoculant was being administered, inappropriately, by unauthorized personnel. The danger was that untrained persons could unintentionally develop the disease themselves or unwittingly spread it through contact, as they wandered freely in the camp. Washington, however, had to revoke his original order. The overriding risk was that an outbreak in the ranks could cripple the Continental Army at a crucial point in the War.[4]

Before the medical staff could begin the mass inoculation, they had to receive the inoculant and then be monitored. Dr. John Homans, a friend and colleague, inoculated Thacher with no ill effects, and the medical staff began to mobilize resources.[5] Temporary facilities had to be prepared where military personnel who had never been exposed could be safely quartered. The location had to be distanced from those who, having had smallpox, were presumed to be immune. Believing in the effectiveness of inoculation, but recognizing its potential dangers, Washington and the Hospital Department enacted two measures which were to go into effect in May of that year. The first measure was designed to prevent illicit, live-virus inoculation by soldiers and civilians in the encampment. Under the supervised plan, inoculated persons, both soldiers and civilians, were temporarily quarantined and monitored in segregated hospitals. The second measure mandated that new recruits would be inoculated upon enlistment, thereby rendered immune before reaching Boston.[6] Once secured against smallpox, the recruits would then reinforce the Continental Army.

Unpublished correspondence of April 4, 1776, signed by Major John Gizzard Frazer (b. 1740), of Massachusetts, authorized Surgeon-General. Dr. David Townsend (1753-1829), of the Continental Army, to appropriate a private house exclusively for use as an inoculation hospital. The logistics were to be in place in April; and the inoculations would commence in May 1776.[7] The home, belonging to the Heirs of John Gould, Esq., was to be converted into a hospital for “two Regiments in the Continental Service,” a total of 1,456 soldiers.[8] Not surprisingly, by July 3, 1776, Thacher, Townsend, and colleagues had been “constantly engaged in this business.” They successfully completed their assignment on August 5, 1776, a four-month period, over which the Army suffered only one inoculation fatality.[9] Thacher’s Journal reveals that the management of smallpox during the Revolutionary War called for rapid policy adjustments.  Washington’s efforts to contain, and to inoculate against, smallpox were essentially tactical decisions.[10]

In April 1781, while stationed at an encampment in the High Lands of New York, near West Point, Thacher was involved in a second mass inoculation involving American combatants and civilians. On April 20, he reported that all soldiers, along with women and children, “who have not had smallpox, are now under inoculation.” In his regiment, which comprised 728 men, 187 had had smallpox and, therefore, were presumed to be immune to re-infection. If these figures are accurate, then about 550 soldiers were to be newly inoculated and monitored; the number of civilians was not indicated.[11]

As Thacher set about the enormous task, he reflected on the severe supply shortages. Preparations normally provided before inoculation were unavailable: these included medicinal mercury and proper nutrition. Since the standard cathartics, calomel and jalap, were unavailable, Thacher and colleagues relied on butternut bark infusions as an emetic, which was to be administered “previous to the appearance of symptoms.”[12] The typical diet in the encampment, which was poor, affected general health. Rations were high in protein and starch. The only choice for the main meal was beef, bread, and salt pork. Even those who were dangerously ill, and prior to inoculation, were given only small rations of rice, sugar, molasses, and tea.[13]

Thacher disclosed that, for two reasons, the induction of the disease did not go well. First, live virus had to be administered to everyone, regardless of health status and age; and, second, although the short-term quarantining of the inoculated person was required, this could not be guaranteed under the circumstances of war; thus, the danger of accidental contagion or of adverse reactions persisted. Thacher’s report, though short on details, implies that some who should not have been inoculated received the inoculant and either developed full-blown smallpox or succumbed to secondary causes: “Some instances have occurred of putrid fever supervening, either at the first onset, or at the approach of the secondary stage, and a few cases have terminated fatally. Many of our patients were improper subjects of the disease, but we were under the necessity of inoculating all, without exception, whatever might be their condition as to health. Of five hundred who have been inoculated, four only have died, but in other instances, the proportion of deaths is much more considerable.”[14] Thacher was deeply disturbed that everyone had to receive the live virus. This course had to be followed, he understood, to avoid serious military consequences.

As a private practitioner before and after the war, Thacher chronicled the history of smallpox in several contexts. In his prolific writings, he honored his colleagues and the profession, and he served the interests of public health. He described, for example, how the inoculation campaign in the civilian sector had been initiated before the Revolutionary War. When smallpox appeared in 1752, the number of inhabitants affected, whether by contagion or inoculation, amounted to 15,734. Of those acquiring it naturally, 514 out of 5,544 died (9.7 percent); 30 of the 2,113 (1.49 percent) who were inoculated died from the procedure.[15] Public hospitals specializing in the treatment of the disease had already been founded. Two had been opened near Boston in 1764: one at Point Shirley, under the direction of Dr. William Barnett, of New Jersey, and at Castle William, in Boston Harbor, under that of Dr. Samuel Gelston, of Nantucket.[16] In 1776, after the British occupation of Boston had ended, smallpox hospitals were established in Cambridge and Brookline, by Drs. Isaac Rand (1743-1822), William Aspinwall (1743-1823), and Lemuel Hayward (1748-1821), whose biographies can be found in Thacher’s 1828 collection.[17] In view of the fact that more than two thousand persons had been inoculated in one year, he proclaimed that specialized hospitals communicated the benefits of the procedure to the public.[18]

When smallpox broke out in 1792, all of Boston underwent the procedure. Despite this great accomplishment, Thacher considered the results to be regrettable because inoculation was performed indiscriminately—that is, without “the requisite attention” to patients during the post-inoculation period, and without exempting those who were not medically fit.[19] Although not elevated (1.8 percent), the mortality rate was nonetheless tragic. Of the 9,152 persons who were prophylactically treated, smallpox had been fatally induced in 165 persons, the majority of whom were the children of poor families.[20] The exigencies of war and disease never compromised his humanity.


[1]James B. Brewster, “James Thacher, M.D., of Plymouth, Massachusetts,” Boston Medical and Surgical Journal124 (June 11 and 18, 1891): 571-73, 596-97; Walter R. Steiner, “Dr. James Thacher of Plymouth, Massachusetts, an Erudite Physician of Revolutionary and Post-Revolutionary Fame,” Bulletin of the History of the Institute of Medicine 1 (1933): 157-73,; Henry R. Viets, “James Thacher and his Influence on American Medicine,” Virginia Medical Monthly (August, 1948): 384-399; Janet B. Joy, “Thacher, James (1754-1844),” in The American Revolution, 1775-1783: An Encyclopedia, Richard L. Blanco, ed. 2 vols. (New York and London: Garland Publishing, Inc., 1993), vol. 2, 1640-41; Ann M. Becker, “Smallpox at the Siege of Boston: ‘Vigilance against this most dangerous enemy,” Historical Journal of Massachusetts 45 (2017): 42-75; Ira M. Rutkow, “James Thacher and his Military Journal during the American Revolutionary War,” Archives of Surgery 136 (2001): 837,; Elizabeth A. Fenn, Pox Americana: The Great Smallpox Epidemic of 1775-82 (New York; Hill and Wang, 2001), 36, 131.

[2]James Thacher, A Military Journal during the American Revolutionary War, from 1775 to 1783 (1823; Boston: Cottons & Barnard, 1827); Brewster, “James Thacher, M.D.,” 596.

[3]Thacher, Military Journal, 43-46.

[4]Mary C. Gillett, The Army Medical Department, 1775-1818 (Washington, D.C.: Office of Medical History, 1981), 74.

[5]Thacher, Military Journal, 43-46.

[6]Gillett, The Army Medical Department, 74.

[7]“Document authorizing Dr. David Townsend, Surgeon General, to appropriate a private house as a hospital for the Continental Army in April 1776,” Manuscript Note, April 4, 1776,

[8]“Document authorizing Dr. David Townsend”; American Revolutionary War: Continental Army Regiments,

[9]Thacher, Military Journal, 46-47.

[10]Becker, “Smallpox at the Siege of Boston”, 63.

[11]Thacher, Military Journal, 250.

[12]Ibid., 251.

[13]Ibid., 250-51.

[14]Ibid., 251.

[15]James Thacher, “History of Medicine in America,” in American Medical Biography: Or Memoirs of Eminent Physicians who have flourished in America, to which is prefixed a Succinct History of Medical Science in the United States, from the First Settlement of the Country, 2 vols. (Richardson & Lord; Cottons & Barnard, 1828), 1:22-85, esp. 22-23.

[16]Ibid., 1:22.

[17]Ibid., 1:13-16, 23-24, 91-95, 286-288.

[18]Ibid., 1:23.

[19]Ibid., 1:23.

[20]Ibid., 1:23-24.

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  • I enjoy reading about the Journal American Revolution, it’s very informant & interesting. It’s interesting to read snipets on people & times of that era. Not many people today give it a 2nd thought.

  • What happened to soldiers who absolutely refused to be inoculated (due to fear, religious reasons, etc.)- were they expelled from the army? Similarly, were non-combatants who refused to be inoculated expelled from the army encampments? What was the smallpox inoculation policy with respect to the Continental Navy?

    • The soldiers that refused? This was a non-issue. What religious reasons were there? Put yourself in the time period we are discussing, This is a time period where “bleeding” was prevalent as a last resort, doing nothing to heal the patient, in retrospect, it did the opposite. Given that an estimated 90% of deaths in the Continental Army were due to small pox, as well as the high mortality rate in the general population it was seen, rightfully so, as a miraculous treatment to a death sentence. There were very few outbreaks after Washington ordered all troops inoculated. That’s all the proof needed.

  • Thanks so much for this interesting summary. Thacher’s journal is indeed a classic of AWI literature. Please explain the meaning of “… the Sixth Continental Army…” in the following:

    “The overriding risk was that an outbreak in the ranks could cripple the Sixth Continental Army at a crucial point in the War.[4]”

    Thank you!

  • I am delighted that Dr. Thacher is getting some attention. His journals and diaries are such great resources for finding out what happened on the medical scene. I used them as resources in my book, “Allegiance: The Life and Times of William Eustis.” Those two, Eustis and Thacher, doctors worked together and knew each other well.

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