Genocide or hokum? In any case, the dreaded disease killed Indians in vast numbers.

Plains Indians kept track of the passing years by winter counts, pictures painted in spirals, often on the smooth inner hide of buffalo robes. Each tribe recorded its own version of what was important. But one event on virtually all Plains Indian winter counts was the “smallpox winter.” The smallpox epidemic of 1837–38 all but destroyed the Mandans and severely reduced the Arikaras and Hidatsas, who also lived in fortified villages along the Missouri River and farmed corn, beans and squash, with buffalo hunting as a sideline. The epidemic tipped the balance in favor of the buffalo-hunting tribes who didn’t farm and whose isolated bands weren’t as hard hit by the smallpox epidemic, in turn altering the world’s image of what an “Indian” looked like. Works Progress Administration murals of the 1930s depicted the likes of Myles Standish and Peter Minuit being greeted by Atlantic Coast tribes clad in Sioux war bonnets and war shirts decorated with glass beads—a costume no Wampanoag or Lenape would have recognized, though the Mandans wear somewhat similar clothing in period paintings by George Catlin and Karl Bodmer. The Plains Indians became the Indians. Period.

Nobody knows exactly how many Indians died of smallpox in the dreadful epidemic of 1837–38. Figures range from a responsible 17,200, based on interviews with the most ravaged tribes of the Plains, to a hyperbolic 150,000. The impact on a relatively small population of hunter-gatherers and now nearly extinct small farmers was on the level of the Black Death in Europe and far beyond the influenza epidemic of World War I in terms of proportional loss of life and reduction of culture—though in fact more Plains Indians may have died of influenza, tuberculosis and pneumonia once confined to reservations on short rations in the 1880s than succumbed to smallpox in 1837–38.

The epidemic of 1837–38 also spawned a narrative of deliberate white genocide against the original Americans: “smallpox in the blankets”—white Europeans and white Americans deliberately promoting the spread of smallpox among unsuspecting American Indians to clear them off the land. Smallpox in the blankets is one of those stubborn legends that can’t be dismissed as myth because it is founded in a mixture of limited historical fact and widespread circumstantial evidence. Based on Raphael Lemkin’s definition of “genocide”— a term he coined in 1944 to describe what the Turks had done to the Armenians during World War I, the Soviets had done to the Ukrainians and upper-class Poles in the interwar period and what the Nazis were then doing to the Jews— the United States had practiced cultural genocide against American Indians since the 1870s, but had not practiced actual physical genocide. The sole documented instance of smallpox in the blankets was approved by an Englishman and instigated by a brace of Swiss mercenaries. White American settlers and soldiers had murdered large groups of Indians, including women and children, from the 17th century to the end of the 19th century with guns, poison and clubs—but they didn’t use smallpox.

American Indians were notoriously vulnerable to contagious diseases. Scientists have theorized that the Asians who migrated over the Bering land bridge millennia ago were exposed to such intense cold that the diseased among them died en route. Isolation from Eurasia and Africa insulated North and South America from such contagious killers as bubonic and pneumonic plague, smallpox and tuberculosis. Archaeologists who have examined natural or manmade Indian mummies have discovered that Indians were susceptible to cancer, arthritis and, rarely, tooth decay but not much else. Syphilis appears to have existed in both hemispheres but wasn’t virulent in the Western Hemisphere as it became in Europe after 1494. Those Paleo-Indians not killed in battle or accident or by starvation died of “old age.”

Smallpox, perhaps augmented by other endemic diseases, had ravaged the mighty Aztecs and Incas at the time of the Spanish conquests and killed more than half the Indians in the Caribbean. But the chain of events behind the one authentic case of deliberate smallpox contamination began in 1757 at the siege of Fort William Henry (in present-day upstate New York), when Indians allied with the French ignored the terms of a surrender worked out between the British and the French, broke into the garrison hospital and killed and scalped a number of patients, some of them suffering from smallpox. The blankets and clothing the Indians looted from the patients in the hospital and corpses in the cemetery, carried back to their villages, reportedly touched off a smallpox epidemic.

The French lost the war and left their Indian allies holding the bag, and in 1763 Chief Pontiac and his colleagues sparked an uprising against English settlers in the Great Lakes region that had Lord Jeffery Amherst and the British forces close to despair. The Indians destroyed several of the smaller British forts, but Fort Pitt (present-day Pittsburgh, Pa.) held out under the command of Captain Simeon Ecuyer, a 22-year veteran Swiss mercenary in the British service. Ecuyer, whose native language was French, also spoke German, the predominant language of his native Switzerland; the British had retained him because many settlers in Pennsylvania also spoke German. Smallpox had broken out among the British garrison, and during a parley on June 24, 1763, Ecuyer gave besieging Lenape warriors several items taken from smallpox patients. “We gave them two blankets and a handkerchief out of the smallpox hospital,” Captain William Trent of the garrison militia wrote in his journal. “I hope it will have the desired effect.”

Smallpox did break out among the Indian tribes whose warriors were besieging the fort—19th-century historian Francis Parkman estimated that 60 to 80 Indians in the Ohio Valley died in a localized epidemic. But no one is sure whether the smallpox was carried by Ecuyer’s infected blankets or by the clothing Indian warriors had stolen from the estimated 2,000 outlying settlers they had killed or abducted.

Ecuyer’s attempt to spread smallpox among the hostile Indians was in no way disapproved. While Colonel Henry Bouquet was preparing to lead a British expedition to relieve Fort Pitt, Amherst sent him a note on June 29: “Could it not be contrived to send the smallpox among the disaffected tribes of Indians? We must on this occasion use every stratagem in our power to reduce them.”

Bouquet, another Franco-Swiss mercenary recruited because he spoke German, wrote back on June 13, “I will try to inoculate the bastards with some blankets that may fall into their hands, and take care not to get the disease myself.” Amherst replied on July 16, advocating exposure to smallpox “by means of blankets, as well as every other method that can serve to extirpate this execrable race.”

Ecuyer, in fact, had acted before receiving orders from Bouquet or Amherst. But a more conventional military solution ended the standoff. On August 1 the Indians broke off the siege to confront Bouquet’s approaching force of 500 soldiers, and at the August 5 Battle of Bushy Run the Scottish and American troops in the British column fought through the Indians to relieve Fort Pitt. The British lost about 50 men, the Indians about the same.

What role smallpox played in mitigating the Indian resistance remains debatable. Battles of Chief Pontiac, a 1952 black-and-white film starring Lon Chaney Jr., Helen Westcott and Lex Barker, tried to blame the smallpox contamination on a Hessian mercenary, played by Barry Kroeger, but the British didn’t import Hessian mercenaries into the Western Hemisphere until the second year of the American Revolution. The actual conspirators were Franco-Swiss acting with English approval.

During the American Revolution the British leadership reportedly suggested infecting George Washington’s troops with smallpox by launching arrows tainted with the toxin into Patriot camps, but nobody seems to have done so. Where the Indians were concerned, they didn’t need to: Their weak immune systems and the lack of sanitation on either side of the conflict made contamination by respiratory diseases exceptionally lethal. As whole tribes came into regular contact with whites, the results were inevitable.

What happened to the Missouri River farming tribes and the Plains tribes in general in 1837–38 was the culmination of three centuries of tragedy. The tribe worst ravaged was the Mandan, a Siouan-speaking farming tribe intermarried, to some degree, with French traders and already decimated by a smallpox epidemic at the end of the 18th century. On July 14, in the ominous summer of 1837, Francis Chardon, Franco-American factor of Fort Clark, an American Fur Company trading post in the Mandan country along the Missouri River, reported that “a young Mandan died today of the smallpox—several others has [sic] caught it.” Chardon later told John James Audubon that a Mandan had swiped a blanket from the infected deckhand of the steam boat St. Peter’s when it stopped for supplies at Fort Clark. Jacob Halsey, another fur company official, reported smallpox shortly after the steamboat stopped at Fort Clark. Halsey himself was quarantined when he reached Fort Union; he recovered from the disease, but it claimed his half-blood wife.

Smallpox exploded among the Mandans. They blamed Chardon, whose respected Lakota wife had recently died, though not of smallpox. But Chardon hadn’t touched off the epidemic and had in fact tried in vain to keep the Mandans away from the steamboat once he learned smallpox was present. Chardon thought the Mandans didn’t compare favorably with the Lakotas—his late wife’s people—but he certainly didn’t want to see them wiped out. They were his bread and butter. The Mandans, however, remained convinced Chardon had somehow contrived to infect them. Would-be avengers stalked him until they themselves keeled over to the awful explosion of smallpox.

The Mandan Chief Four Bears (Mato-tope), always a friend of the whites and much admired by westering artists and even by Chardon himself, died cursing the whites and urging the survivors of his dying tribe to wipe them out:

I have never called a white man a dog, but today I do pronounce them to be a set of black-hearted dogs….I do not fear death, my friends, you know it, but to die with my face rotten that even wolves will shrink with horror at seeing me and say to themselves, ‘That is the Four Bears, the friend of the whites.’

Listen well to what I have to say, as it will be the last time you will hear me. Think of your wives, children, brothers, sisters, friends, and in fact all that you hold dear, are all dead, or dying, with their faces all rotten, caused by these dogs the whites, think of all that, my friends, and rise all together and not leave one of them alive.

The Arikaras also believed the whites had deliberately targeted the Mandans and offered to defend the whites in return for their own tribe’s continued immunity. Then the smallpox broke out among the Arikaras and the Hidatsas as well. An Arikara showed up at the Fort Clark gates to ambush Chardon, but ended up killing a company employee named John Oliver. The white traders then chased down and killed the murderer. The Arikara’s mother asked the traders to kill her as well, but Chardon stopped Oliver’s friends from carrying out the execution.

Clustered in domed earth lodges that sheltered 40 to 50 people, the farming tribes of the Missouri unwittingly passed the disease between families. Even those Mandans not infected by smallpox sometimes killed themselves out of fear, despair or grief. Two infected warriors reportedly debated the best way to die; one cut his own throat, and the other forced an arrow through his lungs. A widow killed her two children and then hanged herself. One man shot first his wife and children, then shot himself with a trade musket by pulling the trigger with his toe. Others jumped off cliffs or drowned themselves when they developed the dreaded symptoms of smallpox.

The hunting tribes of the Plains had immune systems every bit as vulnerable as those of the Mandans, but because the Plains tribes lived in small summer bands of hunters, they were isolated from the wholesale contamination that decimated or destroyed the tribes who lived in fortified villages.

The horrors observed by white traders on the Upper Missouri were all but incredible. “Nothing but an occasional glass of grog keeps me alive,” Chardon wrote in his journal. His own beloved son, named after President Andrew Jackson, was among the victims. When Alexander Culbertson, husband of two successive Blackfoot wives whom he respected and in one case adored, went out in search of his customers, he found whole encampments full of spotted corpses— “hundreds of decaying forms of human beings”—scattered among the lodges. The victims had also sacrificed their horses and dogs, perhaps to ward off infection or to accompany their owners to the next world. Culbertson also contracted the disease but survived. The Blackfeet lost upward of 6,000 people; once the scourge of trappers and warriors on the level of the Lakotas, they abruptly ceased to be a threat to expansion.

After Fort Union trader Jacob Halsey discovered he had contracted smallpox, he and his associates decided to develop a vaccine—but they went about it the wrong way. Smallpox vaccine was correctly made from the virus that causes cowpox, a seldom-lethal disease endemic among English milkmaids. In the late 18th century, English country physician Edward Jenner developed the vaccine from cowpox pus after observing that the recovered milkmaids also seemed immune to smallpox. The Chinese had employed a similar vaccination method for centuries—inhalation of dried, powdered smallpox scabs reportedly induced immunity in Chinese peasants, though the peasants may have secured immunity by exposure to cowpox among their own plow oxen. Halsey, however, made his vaccine with pus from his own virulent smallpox, rather than irritating but harmless cowpox. The results were inevitable: Those Indians who didn’t catch the smallpox from actual victims contracted it from Halsey’s well-meaning but misguided vaccination effort. Oddly enough, the vaccine seems to have worked reasonably well—only a few of the 30-some inoculated people, white traders and their Indian wives and mixed-blood children, actually died.

The Assiniboins reacted to the arrival of smallpox in their villages by burning the American flag and asking for liquor to have a good time before the inevitable. Most survived, but they ceased to be key players in frontier warfare. The Assiniboins at Fort Union, however, carried the disease to their lodges in Canada and out onto the Plains, possibly infecting other tribes.

Two Crow warriors from a village near present-day Billings, Mont., contracted smallpox but put their families and friends ahead of their own survival, choosing to leap from a cliff rather than spread the disease. But smallpox spread in other Crow camps, claiming an estimated third of the tribe.

Commissioner of Indian Affairs Carey A. Harris estimated that 17,200 Indians died of smallpox in 1837–38, based on numbers from the main tribes involved: Mandan, Hidatsa, Arikara, Lakota, Assiniboine and Blackfoot. Smallpox also struck the “Five Civilized Tribes”—Cherokee, Chickasaw, Choctaw, Creek and Seminole—then being relocated from the South to Indian Territory (present-day Oklahoma).

The results of the 1837–38 smallpox epidemic were doubly catastrophic: Huge numbers of Indians died, and along with them went the hope that Western Indians could thrive as farmers. Because the worst-hit tribes were agricultural, the Indians themselves came to view farming as a death trip. Thomas Gallagher, in his 1982 book Paddy’s Lament, notes that 19th-century Irish immigrants, most of whom had been farmers back in Ireland, had no desire to farm in America because the potato blight of 1845–48 had been a starvation trip for them. The immigrant Irish gravitated toward jobs with police and fire departments, the railroads and the Army, and later toward Democratic politics. The 1837–38 epidemic had a similar impact on many Plains Indian tribes. With few exceptions—the Nakota, the Ponca and the survivors of the Arikara and the Hidatsa—the tribes moved into a buffalo-or-bust culture and to active warfare as either enemies or allies of the U.S. Army.

Once the soldiers had rounded up the survivors and confined them to reservations beginning in the 1870s, another wave of diseases hit. Smallpox had long since been under control, but tuberculosis and pneumonia, carried by whites and endemic among people whose houses weren’t well ventilated, wiped out scores of the first generation of Indians born on the reservations. Measles—scourge of the Polynesian Hawaiians—and whooping cough, which arrived on the reservations in the 1880s, also killed large numbers of Indians. The Indians blamed outbreaks on the “square houses” they were forced to live in once the shortage of buffalo hides forced them to abandon tepee life. In a sense they were right: Tepees were well ventilated compared to the houses they built under white supervision. Adding to the Indians’ woes were their ever-vulnerable immune systems and malnutrition due to the poor reservation diet. American Indians have long blamed smallpox in the blankets for their destruction. The Crows, bitter enemies of the Lakotas, extrapolated the idea that smallpox infection was regular U.S. policy. Crow Chief Blackfoot, an ally of the whites, said to Indian commissioners three years before Custer’s Last Stand: “You ought not to give the Sioux guns and ammunition; you should wipe them all out; you should throw a disease upon them.”

Whether any individual in the real West ever tried to spread smallpox in blankets is unsubstantiated and debatable. Nevertheless, the practice has made it way onto film as recently as 2006. In a memorable scene from the Emmy-winning TV miniseries Broken Trail, Robert Duvall’s character effectively deals with “Smallpox Bob,” a despicable white trader who sells infected blankets to the Plains Indians.

The dreadful epidemic of 1837–38 and smallpox in general did not come to American Indians through any scheme of the U.S. Army. The only documented attempt to infect Indians with smallpox was the dirty work of Swiss mercenaries serving the British crown before the United States’ founding as a constitutional republic. American Indians did indeed succumb in huge numbers to smallpox, measles, tuberculosis and influenza, due to contact with whites, the Indians’ own feeble immune systems and malnutrition once rounded up and sequestered on the reservations. That was a cultural catastrophe, a heart-rending tragedy—but it was not premeditated genocide.


 John Koster is the author of Custer Survivor (2010) and Operation Snow: How a Soviet Mole in the White House Triggered Pearl Harbor (2012). Suzie Koster and Jessica Mok helped research this article. For more on the 1837–38 smallpox epidemic read Across the Wide Missouri, by Bernard DeVoto.

Originally published in the August 2012 issue of Wild West. To subscribe, click here.