“The number of sick increasing every day, in all the different Camps of the army,” wrote Capt. John Peebles in his diary on September 5, 1779. Encamped on Manhattan Island eight miles north of the city of New York, at the time rural farmland, the army was beginning to suffer from the consequences of an unusually rainy and windless summer. On August 24 Peebles, who commanded the grenadier company of the 42nd Regiment of Foot, part of the army’s grenadier battalion, noted that the light infantry battalion was moving to Long Island from the “wet swampy ground” they had been camped upon because men in the battalion were getting sick. Seven days later he wrote, “The Men growing very sickly within these few days, a general complaint over the whole army, they are mostly taken with headache & universal pain a chill & feverishness, which for the most part turns into a quotidian or tertian intermittent, & some few are rather with the flux.” Twelve men in his one-hundred-man company had fallen ill, six within the last twenty-four hours. It was only the beginning.
Techniques for keeping an army healthy were well-known to the British army in America. A century of corporate knowledge was reinforced by a host of textbooks that aggregated experience from Europe’s professional armies. For the most part, officers knew how to choose ground for encampments and cantonments based on prevailing winds and sunlight as well as tactical considerations, and the importance of things like drainage, refreshing the straw used for tent and barrack bedding, burying offal and waste well away from habitations, frequently relocating “necessary houses” (latrines), and providing adequate ventilation in hospitals and barracks, was well known. When the weather and location permitted, soldiers bathed regularly in rivers or the sea. It was rare for sickness to ravage the British armies in Canada and New York. But the autumn of 1779 was different.
The “quotidian or tertian intermittent” fevers that Captain Peebles wrote of were familiar in a general sense. British army surgeon Thomas Reide divided fevers into two categories, remitting and inflammatory, noting that some fevers showed characteristics of both. As the name suggests, remitting fevers recurred every day or two. Many writers used the term “ague,” meaning malarial fever, for any remitting fever regardless of whether malaria was known to have been the cause. Reide called remitting fever “the most common disease that mankind is attacked with.” He described an assortment of symptoms; the fever’s onset was characterized by “chilliness, lassitude, yawning; pains of the head, back and bones, vertigo, anxiety, nausea, and oppression of the stomach.” Next came “heat, dry skin, thirst, parched tongue, though sometimes white and moist; violent head-ache, difficulty of breathing, delirium, restlessness, frequent hard pulse, bilious vomiting and loose stools, sometimes with worms; often costiveness, with a hardness of the belly, and flatulency; high-coloured urine, yellowness of the eyes, and frequently of the whole body.” These fevers were remitting because “generally in a short time a copious perspiration” occurred, followed by some relief of symptoms. But the symptoms came back, sometimes every day, sometimes every other day, “sometimes it is quite irregular. The exacerbation is generally at night, and the remission in the morning.”
Captain Peebles observed on September 5 that the army’s sick men had “nearly the same complaint vizt a fever from Accumulated Bile more or less continued, according to the load or treatment of the patient & terminates in remissions, or intermissions with an ague.” The next day he observed that some 200 men of the grenadier battalion, about a quarter of its strength, were hospitalized. By the end of the month, when a fresh breeze arose, he observed with concern, “I hope this weather will be of service to the sick & check the progress of the disease, which is still seizing on new subjects & but very few of the old recovering.” On October 1, “The number of sick still increases, some few fluxes which has carried off some men, but the general complaint is an undistinct remitting & intermitting fever, with & without more or less of an ague which proves more lasting & obstinate as their great numbers does not admit of that care, treatment & attention that is necessary.” The numbers of stricken men put a strain on the army’s medical personnel. The grenadier battalion had, on October 1, “Only one Hospital Mate to attend 130 or 40 Sick, & few comforts.”
It wasn’t until mid-November that Peebles was able to report, “The Sick recovering but slowly,” a phrase he repeated a week later (November 21), adding, “29 in the Doctors lists, & 12 convalescents many relapses.” His last mention of the outbreak was on December 3, when he wrote that “the no. of sick decreasing.”
Captain Peebles’ grenadier company fared well in the long run, with only three deaths during the time of fever. The 37th Regiment, in which nearly every man in its eight battalion companies had been sick, lost thirty-five men from August thru December including fifteen newly-arrived recruits and drafts. The 54th Regiment, encamped on Long Island, fared even worse, with sixty-six deaths in the seven battalion companies for which muster rolls survive, almost fifteen percent of its strength.
What was the cause of this outbreak, the likes of which had not occurred before during the war in this region, and did not occur again, even though the army occupied much the same ground from the autumn of 1776 through the autumn of 1783? Army surgeon Robert Jackson recognized that some camps on the northern end of Manhattan were situated too close to unhealthy locations. “The situation of the encampment which the 71st regiment occupied at King’s-bridge, in the year 1778, affords a curious and direct” example, he remembered. “About two hundred paces to the right of the spot, on which the tents were pitched, was a tract of low and swampy ground; but the immediate situation was dry, and of considerable elevation. The right was particularly so; yet it was principally on the right, where the disease raged with violence. The left, though on low ground, over which fogs frequently hung till late in the day, suffered a much smaller proportion.” He also recognized that “the great degree of sickness, which happened to those people, who not being confined by the nature of their duty to one particular spot, pitched their tents on a hill in the rear of the encampment” proved that it was not elevation and dryness alone that made the difference. “The ground, which those persons made choice of was directly in the tracts of air, which blew over the swamp. It was dry and scarcely ever covered with fogs; yet there was not an individual among them who encamped upon it, who did not suffer from this raging epidemic.” Jackson understood the connection between the swamp and the sickness, even though he didn’t know the vector—probably mosquitoes—that connected the two.
When the 1779 outbreak began, Captain Peebles, noticing that it was afflicting soldiers and civilians alike on Manhattan and Long Island, thought it was “owing probably to the great deal of rainy weather we had lately, more than any body remembers, with little or no thunder.” There was, however, another factor that may have been at play. In late March, just over 1,300 recruits had embarked in Portsmouth, England, along with four British regiments and number of recruits for German regiments. They sailed in April, but the transports soon dropped anchor in Torbay while their escorting warships went to help fend off a French attempt to seize the islands of Jersey and Guernsey. It was a month before the convoy was under way again, finally arriving in New York in late August. The troops had been on ships for nearly five months, and eight hundred were sick, including almost three hundred British recruits; forty-three more recruits had died during the passage. The admiral commanding the convoy was confident that the malady was “principally scurvy” and that most would “soon recover.” They did not. Of sixty-three recruits for the 22nd Regiment, twenty-six died within a year, as did thirty-four out of one hundred and six for the 38th Regiment. They may have brought pestilence with them, or been vulnerable after their long sea voyage.
Gen. Henry Clinton, commanding the afflicted garrison, called the outbreak a “malignant jail fever,” suggesting a belief that it was brought by the recruits. A board of army doctors convened to examine “the present extraordinary unhealthy state of the Army,” on the other hand, recognized that the first cases of fever had occurred before the convoy from Britain arrived. Commencing “about the middle of July, & has continued to increase ever since,” it had “attacked the Natives of all Conditions, & Ages, on the Islands of New-York, Staaten & Long Islands,—previous to the unhealthy State of the Military.” The board concluded that the “Intermittent, Bilious Fever, & Dysenteries” that swept through the army and civilian population were caused by “the frequent heavy rains, succeeded by unusual, calm, sultry Weather, with the defect of Thunder, and Lightning Common to the Climate,” but also noted that “the chief Mortality in the Hospitals has been amongst the Troops which arriv’d from England on the 25th August owing to a contagious Fever that they brought with them.”
Muster rolls, 54th Regiment of Foot, WO 12/6399, British National Archives. The regiment consisted of ten companies, but two of them, the grenadiers and light infantry, were detached and not camped at the same location as the remaining eight companies.