Did George Washington order troops to be vaccinated?
No. Vaccination didn't exist yet, he had them inoculated — which was more dangerous, but still effective and better than dying of smallpox.
On the 6th of January 1777, George Washington wrote to Dr. William Shippen Jr., ordering him to inoculate all of the forces that came through Philadelphia. He explained that: "Necessity not only authorizes but seems to require the measure, for should the disorder infect the Army . . . we should have more to dread from it, than from the Sword of the Enemy." The urgency was real. Troops were scarce and encampments had turned into nomadic hospitals of festering disease, deterring further recruitment. Both Benedict Arnold and Benjamin Franklin, after surveying the havoc wreaked by Variola in the Canadian campaign, expressed fears that the virus would be the army's ultimate downfall. (Fenn 2001, 69)
At the time, the practice of infecting the individual with a less-deadly form of the disease was widespread throughout Europe. Most British troops were immune to Variola, giving them an enormous advantage against the vulnerable colonists. (Fenn 2001, 131) Conversely, the history of inoculation in America (beginning with the efforts of the Reverend Cotton Mather in 1720) was pocked by the fear of the contamination potential of the process. Such fears led the Continental Congress to issue a proclamation in 1776 prohibiting Surgeons of the Army to inoculate.
Washington suspected the only available recourse was inoculation, yet contagion risks aside, he knew that a mass inoculation put the entire army in a precarious position should the British hear of his plans. Moreover, Historians estimate that less than a quarter of the Continental Army had ever had the virus; inoculating the remaining three quarters and every new recruit must have seemed daunting. Yet the high prevalence of disease among the army regulars was a significant deterrent to desperately needed recruits, and a dramatic reform was needed to allay their fears.
Weighing the risks, on February 5th of 1777, Washington finally committed to the unpopular policy of mass inoculation by writing to inform Congress of his plan. Throughout February, Washington, with no precedent for the operation he was about to undertake, covertly communicated to his commanding officers orders to oversee mass inoculations of their troops in the model of Morristown and Philadelphia (Dr. Shippen's Hospital). At least eleven hospitals had been constructed by the year's end.