Section 3: Smallpox Epidemic of 1837

Smallpox epidemics had struck the tribes of the Upper Missouri at least twice before the terrible epidemic of 1837. The earlier epidemics of 1781 and 1801 took the lives of thousands of Mandans, Hidatsas, and Arikaras and forced them to move north to re-build their villages near the mouth of the Knife River. However, not long after the earthlodge villages became established on the Knife, they experienced the worst smallpox epidemic ever.

Fort Clark was a fur-trading post that had been built in 1823 just a few miles south of the mouth of the Knife River on the west bank of the Missouri River. One-quarter mile from the fort was the Mandan village of Mitu'tahakto's (meh TOOT ah hahnk tosh). Within 15 miles of the post were several more Mandan, Arikara, and Hidatsa villages. Earlier epidemics and inter-tribal conflict had forced the earthlodge peoples north to the Knife River. The Yanktonais, Crows, Assiniboines and other tribes traveled to Fort Clark bringing buffalo robes and furs to trade for tobacco, guns, cloth, and other goods. Fort Clark was a busy, densely populated center of international trade.

On June 18, 1837, the steamboat St. Peters approached Fort Clark. In addition to supplies, the St. Peters brought Andrew Jackson Chardon, the two-year-old son of Fort Clark’s superintendent, Francis Chardon. Chardon met the boat some 30 miles downstream. He removed his son from the boat and heard the news that people on the boat were infected with smallpox.

When the steamboat landed at Fort Clark, people came and went from the boat to the fort and the villages.  Workers from the boat and the post unloaded goods and loaded bales of furs. All of the activity took place in less than 24 hours amid a “frolick” of singing and dancing and celebration. Once loaded, the St. Peters headed upstream to Fort Union carrying the deadly virus.

On July 14, 1837, Chardon noted in his journal that a Mandan man had died of smallpox in the village. (See Document 2.) ChardonChardon was a hard-drinking man who was not known to be fond of Indians, but as he slowly became aware of the devastation caused by smallpox, he began to agonize over the situation of his trading partners, especially the Mandans. Six years later, Chardon spoke to John James Audubon about the epidemic when Audubon visited Fort Clark. Audubon recorded Chardon’s words in his journal: “[Chardon assured] us all that the small-pox had never been known in the civilized world, as it had been among the poor Mandans and other Indians.” knew that smallpox would become an epidemic and that many more would die, but the extent of the epidemic stunned him. He recorded the deaths of important village leaders including the highly-respected second chief of the Mandans, Four Bears. He heard, probably second-hand, the death-speech of Four Bears (See Document 2, entry for July 30.) and recorded it in his journal.

Chardon was unable to keep track of the number of deaths: “they die so fast that it is impossible,” he wrote. Survivors swore revenge against Chardon for bringing death to their villages. There were murders and threats of murder as the deeply despairing Mandans tried to avenge the deaths of their families and friends. Some people, sick with smallpox or feeling desperate from the loss of every member of their family, committed suicide. Suicide was unknown among the Mandans and Hidatsas before the epidemic.

Before the disease reached the post, Chardon sent his oldest son downriver to Fort Pierre. The boy was sent on to his grandparents’ home in Pennsylvania. The younger son, Andrew Jackson, remained with Chardon (the boy’s mother had died in April before the epidemic). When the disease finally penetrated the walls of the fort, Andrew Jackson sickened and died as did many other young children of the post employees.

When the disease reached Fort Union, more people, both Indians and non-Indians, were exposed and suffered. The superintendent at Fort Union tried to inoculate as many people as he could. Many tribes fled the area and probably saved many lives in doing so. The disease however, continued to spread across the northern Great Plains where the Indians had been denied access to the 1832 federal vaccination program.

The Mandan people suffered the greatest losses in the epidemic. Frequent, close contact among the people of the villages and the fur trade post helped to spread the disease quickly. About 2,000 Mandans lived in the Knife River villages in the spring of 1837. By October, 138 people remained alive. The survivors moved from the village at Fort Clark to other villages. The Arikaras, who had lost perhaps two-thirds of their population, moved into Mitu'tahakto's. They harvested the Mandans’ garden crops that year and remained in the village near Fort Clark.

Document 2. Smallpox at Fort Clark, 1837

In 1837, an outbreak of smallpox on the Upper Missouri River killed approximately 90 percent of all Mandans and one-half of the Arikaras (“Rees”) and Hidatsas (“Gros Ventres”). Most of these people lived in villages near the American Fur Company trading post, Fort Clark. The density of population and the constant travel to hunt and trade helped to spread the disease. The superintendent at Fort Clark was Francis A. Chardon. Daily entries in his post journal tell of the spread of the smallpox epidemic.

As people faced overwhelming loss, they sought revenge on Chardon. They legitimately blamed the white traders for bringing the disease among them. Some tried to kill Chardon, but he kept his men on alert to prevent an attack on himself or on the fort. Chardon was able to protect himself and his fort from attack, but the disease took the lives of his youngest son and many others living in the post.

The loss of loved ones and friends caused a great deal of despair. In some cases, Mandans or Hidatsas committed suicide. Chardon notes these suicides because, before the epidemic, suicide was almost unknown among the three tribes. Suicide was a sign of how deeply they felt the loss of their families and friends.

Chardon’s journal reveals how daily life was interrupted by the epidemic. The survivors would need meat and crops to get through the coming winter, but there were few people healthy enough to do the work. Chardon did not have enough workers to get hay and winter firewood supplies into the post. The gardens of the Mandans and Hidatsas suffered from heat and drought, and there were few healthy women to manage the harvest. In addition, the Yanktonais (Sioux) threatened and attacked the weakened villages.

Chardon wrote that some elderly Mandans and Hidatsas had survived the 1837 outbreak because they had had the disease in “Old times.”  These elders had been exposed to smallpox in 1801 or perhaps as early as 1781. They survived in 1837 because once they had the disease, they were immune.

These journal entries have been edited for easier reading, though much of the original spelling remains. You will find some terms such as “squaw” which were in common use in Chardon’s day. The word “squaw” is used today only in historical documents.

You can read all or part of Chardon’s journal online:

April 1837 [page 109]

Monday 24— The Mandans . . . report cattle [bison] far off, and scarce. . . Trade going on slow —

June 1837 

Sunday 18 — . . . The Steam Boat St. Peters hove in sight at 2 P. M. —Capt Pratte, with Mr. Papin & Halsey on Board, with two Mackinaw Boats that she was towing up as far as Fort Clark to take down the returns of that Post —

Monday 19 — . . . arrived at the Mandans at 3 P. M., onloaded [from the St. Peters] the Merchandises for the Fort [Clark] — all hands a Frolicking, found my hunters Out —

Tuesday 20— The Steam Boat left here this Morning early for Fort Union, the Agent for the Mandans has gone [to Fort Union]— Halsey has went up to reside at Fort Union — My Hunters arrived with plenty of fresh Meat —

July 1837

Friday 14 — One of the warmest days that we have had this summer — Weather smokey — A young Mandan died to day of the Small Pox — several others has caught it — the Indians all being out Makeing dried Meat has saved several of them —

Monday 17 — An other case of the small pox broke out to day at the Village —

Thursday 20 — Sent Mitchel with two Men . . . to the Ree Camp, to trade Meat —. . . Mr May and Yoyo arrived from the Little Missouri With two Mules and one horse — No News in that quarter, except the Small Pox.

Tuesday 25 — Several Young Men arrived from the dried Meat Camp. . . . They will all be in to morrow — they say that the small pox has broke out at the Camp —

Wednesday 26— The Rees and Mandans all arrived to day well loaded with Meat, Mitchel also arrived with 150 pieces. The 4 Bears (Mandan) has caught the small pox, and got crazy and has disappeared from camp — he arrived here in the afternoon— The Indians of the Little Village all arrived in the evening well loaded with dried Meat — the small pox has broke out among them, several has died. . .

Thursday 27 — Indians all out after berries. No News from any quarter. The small pox is Killing them up at the Village, four died to day . . .

Friday 28 — Rain in the Morning — This day was very Near being my last — a Young Mandan came to the Fort with his gun cocked, and secreted under his robe, with the intention of Killing me, after hunting me in 3 or 4 of the houses he at last found me, the door being shut, he waited some time for me to come out, just as I was in the act of going out, Mitchel caught him, and gave him in the hands of two Indians who conducted him to the Village, had not Mitchel perceived him the instant he did, I would not be at the trouble of Makeing this statement — I am upon my guard, . . . I have got 100 Guns ready and 1000 lb Powder, ready to hand out to them when the fun commences — The war party of Rees that left here the 7th . . . came back to day — with five horses, that they stole from the Sioux—they attacked it in the night, after fireing several shots they departed, takeing with them all the Horses— they think to have Killed 3 or 4 in the lodge—The Mandans & Rees gave us two splendid dances, they say they dance, on account of their Not haveing a long time to live, as they expect to all die of the small pox —and as long as they are alive, they will take it out in dancing —

Saturday 29— Several more Mandans died last night. Two Gros Ventres [Hidatsas] arrived from their dried Meat Camp, it appears that it has not broke out among them as yet —

Sunday 30 — An other report from the Gros Ventres to day say, that they are arrived at their Village, and that 10 or 15 of them have died, they threaten Death and Distruction to us all at this place, saying that I was the cause of the small pox Makeing its appearance in this country — One of our best friends of the Village (The Four Bears [Mato Tope]) died to day, [his death] regretted by all who Knew him.

July 30th
Speech of the 4 Bears a Mandan Warrior to the Arricarees and Mandans, 30th July 1837 —

My Friends one and all, Listen to what I have to say — Ever since I can remember, I have loved the Whites, I have lived With them ever since I was a Boy, and to the best of my Knowledge, I have never Wronged a White Man, on the Contrary, I have always Protected them from the insults of Others, Which
they cannot deny. The 4 Bears never saw a White Man hungry, but what he gave him to eat, Drink, and a Buffaloe skin to sleep on, in time of Need. I was always ready to die for them, Which they cannot deny. I have done every thing that a red Skin could do for them, and how have they repaid it! With ingratitude! I have Never Called a White Man a Dog, but to day, I do Pronounce them to be a set of Black harted Dogs, they have deceived Me, them that I always considered as Brothers, has turned Out to be My Worst enemies. I have been in Many Battles, and often Wounded, but the Wounds of My enemies I exhalt in, but to day I am Wounded, and by Whom, by those same White Dogs that I have always Considered, and treated as Brothers. I do not fear Death my friends. You Know it, but to die with my face rotten, that even the Wolves will shrink with horror at seeing Me, and say to themselves, that is the 4 Bears the Friend of the Whites —Listen well 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 those dogs the whites, think of all that My friends, and rise all together and Not leave one of them alive. The 4 Bears will act his Part —

August 1837
Tuesday 1st —. . . The Mandans are Makeing their Medicine for rain, As their Corn is all drying up — to day we had several light showers —

Saturday 5 —. . . Indians out after berries, others out after Meat — News from the Gros Ventres, they say that they are encamped this side of Turtle Mountain, and that a great many of them have died of the small pox — several chiefs among/ them. They swear vengence against all the Whites. . .

Sunday 6 — One More Ree [Arikara] died last Night — To day we had a tremendous storm of rain, hale, and wind

Monday 7 — Six More died to day — several Rees left the Mandan Village, and Pitched their Lodges Out in the Prairie, rain all day— report from the Gros Ventres say they will be at their Village tomorrow

Tuesday 8 — Four More died to day — the two thirds of the Village are sick, to day I gave six pounds of Epsom salts in doses to Men, Women, and children, the small pox has broke out at the Little Mandan Village — three died yesterday, two cheifs —

Wednesday 9 — Seven More died to day — the Men came back from the hay — at full speed haveing saw enemies, all hands out for the fight, False alarm.

Thursday 10 — All the Ree's that were encamped in the Mandan lodges, except a few that are sick, Moved down to the Island hopeing to get rid of the small pox — the Mandans talk of Moveing to the other side of the river, 12 or 15 died to day —

Friday 11 — Sent old Charboneau up to the Gros-Ventres with some tobacco, and a bag full of good talk, as yesterday they sent a very severe threat to me. Mandans all crossed to the other side of the river to encamp - leaveing all that were sick in the Village, I Keep no [account] of the dead, as they die so fast that it is impossible —

Saturday 12 — Cool and pleasant weather, one of my best friends of the Little Village died to day—

Sunday 13 — Several reports from the Gros Ventres that they are bent on the distraction [destruction] of us all, as yet I do not place Much confidence in what report says, Charboneau will bring us the strait News — The Mandans are dying 8 and 10 every day — an Old fellow who has lost the whole of his family to the Number of 14, harrangued to day, that it was time to begin to Kill the Whites, as it was them that brought the small pox in the Country—

Monday 14 — Charboneau arrived late last night, all the reports from the Gros Ventres, it appears to be without foundation, as they say, they never had any thoughts of Killing the Whites, but that the Rees, have made several threats, Which of the two to believe, I Know not, however, I will still be on my guard. (The White Cow) a Mandan cheif came early this Morning and appeared to be very angry — telling me that I had better clear out, with all the Whites, that if we did not, they would exterminate us all. I told him that we would not leave the place, and that if they were disposed to Kill us to Come on quick, that we were ready for them at all times. The Rees are Makeing Medicine for their sickness. Some of them have made dreams, that they talked to the Sun, others to the Moon, several articles has been sacrifised to them both — the Principal Chief of the Mandans died to day—The Wolf Cheif)—An other dog, from the Little Village came to the Fort naked with his gun cocked, to Kill one of us, We stopped him —

Tuesday 15 — Gardepie [a trapper] with an other half breed arrived last evening from the North. . . . they left here early this Morning, the small pox scared them off—J. B. Jonca a half breed Kanza [Indian], who has been liveing with the Gros Ventres several years, came on horse back at full speed to inform us that the Mandans went up to the Gros Ventres with a pipe, to Make them smoke, to try to get them to help them to Murder us, the Gros Ventres refused to smoke with them, saying that they were friendly to the Whites and that they would not take part with them. Jonca started back immediately. The War Party of Rees and Mandans that left here the 26th of June, all came back to day, haveing Killed seven Sioux, Men, Women and children, two Lodges that were camped at the Mouth of White River. It appears that the small pox has broke out amongst the Sioux, as some of the Party, on their way back, was taken sick at Grand River, haveing caught the disease from those that they butchered.

Wednesday 16 — Cold for the season, fire, very comfortable. May started up to see his friends the Gros Ventres. Several Men, Women, and Children that has been abandoned in the Village, are laying dead in the lodges, some out side of the Village, others in the little river not entered [buried], which creates a very bad smell all around us — A Ree that has lost his wife and child threatened us to day — We are beset by enemies on all sides — expecting to be shot every Minute —

Thursday 17 — . . . the Indians dying off every day — Where the disease will stop, I Know not —We are badly situated, as we are threatened to be Murdered by the Indians every instant, however we are all determined, and Prepared for the worst — A Young Ree for several days has been lurking around the Fort, watching a good opportunity to Kill me, but not finding a good chance, this Morning he came, full intent to sit himself down in front of the Fort gate, on the [fur] Press, and waited a few Minutes for me to go Out, in the Meantime one of my Men a Dutchman, John Cliver— stepped Out and sat himself down a long side of the Indian, after setting a few Minutes, he got up to come in the Fort, he only Made five paces, when the Indian, shot him in the back bone and Killed him instantaniously, he made off immediately — We pursued after him shooting at him, but without effect — he got as far as the little river, w[h]ere one of his Brothers is entered [buried], on arriving there he made a stop, and [shouted] to us that, [here] was the place he wanted to die. Garreau [a competing trader]. . . approached in 15 paces of him and shot, . . . Knocked him over. He then rushed on him with his large Knife and ripped his body open. . . . I have hoisted the Black flag [a sign of disease] —Garreau deserves the highest praise from us all, he acted manfully although against his own nation [Garreau’s mother was Arikara]— he always told me that he would always act as he has done — the Mother of the fellow we Killed, came to the Fort crying, saying that she wanted to die also, and wished for us to Kill her. [They did not kill her.]

Friday 18 — An old Ree started this Morning to pay a visit to the Gros Ventres, the Soldiers would not let him enter the Village, they have made a quarantine and they will permit no one from this place to come near them. . . . Nothing but an occasional glass of grog [whiskey] Keeps me alive as I am worried almost to death by the Indians and Whites, the latter (the men) threaten to leave me.

Saturday 19 — a Mandan and his Wife Killed themselves yesterday, to not Out live their relations that are dead — Sent ten Pounds of tobacco to the Soldiers of the Gros Ventres, begging them to Not come to their summer Village, as the disease has not yet broke out amongst them, if it does I am afraid that they will put their threats in execution, I was in hopes that the disease was almost at an end, but they are dying off 8 and 10 every day — and new cases of it daily — Where it will stop God only Knows — As I was sitting out side of the Fort, an Indian came to me, and told me that I had better go in the Fort, as it was dangerous for me to go out — I took his advice and went in, although ashamed to say so —In the hurry and confusion on the 17th some dog [enemy] made way with one of my guns — the disease broke out in the Fort six days ago.

Sunday 20 — Sprinkled with rain. Three more died in the Village last night — The Wife of a young Mandan that caught the disease was suffering from the pain, her husband looked at her, and held down his head, he jumped up, and said to his wife, When you was young, you were hansome, you are now ugly and going to leave me, but no, I will go with you, he took up his gun and shot her dead, and with his Knife ripped open his own belly — two young men (Rees) Killed themselves to day, one of them stabbed himself with a Knife, and the other with an arrow — Visited by four young men of the Little Village, there has been but eight deaths at their Village, gave them a pipe of tobacco, and they went off — Several showers of rain throughout the day — a Ree that has been liveing in the Fort, for some time past, caught the disease to day — sent him to the Village — A young Ree that has been sick for some time with the small pox, and being alone in his lodge, thought that it was better to die, than to be in so much pain, he began to rub the scabs untill blood was running all over his body, he rolled himself in the ashes, which almost burnt his soul out of his body — two days after he was perfectly well, it is a severe operation, but few are disposed to try it —however it proved beneficial to him. . .

Monday 21 —Indians that left here the 17th in search of cattle [bison], all came back to day with an abundance of Meat — report cattle scarce and far off — The brother of the dog [enemy] we Killed the 17th arrived to day — as yet we have heard nothing from him. I am in hopes that it will all turn out well — An Indian came and told me to be on my guard — as the fellow above mentioned is determined to Act as his brother, to Kill one of us, and then die, he says that he will do it even if all the Village is against him. . .

Tuesday 22 — Cool pleasant weather. The disease still Keeps ahead 8 and 10 die off daily, Thirty five Mandans [Men] have died, the Women and children I Keep no account of — Several Mandans have came back to remain in the Village. One of my [employees]—(Ree) died to day — Two young Mandans shot themselves this Morning — News from the Little Village, that the disease is getting worse and worse every day, it is now two months that it broke out . . . a report is in Circulation, that they intend to fire the Fort — Stationed guards in the Bastion.

Wednesday 23 — The Little Sioux a Mandan died last Night.

Thursday 24 — Seven More died at the Village last Night, and Many More at the Ree camp at the Point of Woods below —The fellow that we Killed on the 17th all his band Came to day to smoke with us and Make Peace, how long it will last I cannot tell, however We Must put up with it, good or bad.

Friday 25—sent a few pounds of powder & Balls to the Gros Ventres and Rees — An other Mandan cheif died to day— total Number of Men that has died —50.

Saturday 26 — The Indians all started Out on the North side in quest of Buffaloe, as they have Nothing to eat — A young Ree, the nephew of Garreau, died at the Village last night, [His death] Much regretted by us all. . . . A young Ree that has the small pox, told his Mother to go and dig his grave, she accordingly did so — after the grave was dug, he walked with the help of his Father to the grave, I Went Out with the Interpreter to try to pursuade him to return back to the Village — but he would not, saying for the reason that all his young friends were gone, and that he wished to follow them, towards evening he died —

Sunday 27 — News from the Gros Ventres of the disease breaking out amongst them.

Monday 28 — Three more fell sick in the Fort to day — My Interpreter for one, if I loose him I shall be badly off —

Tuesday 29 — Last Night I was taken very sick with the Fever, there is six of us in the Fort that has the Fever, and one the small pox — An Indian Vaccinated his child, by cutting two small pieces of flesh out of his arms, and two on the belly —and then takeing a Scab from one, that was getting well of the disease, and rubbing it on the wounded part, three days after, it took effect, and the child is perfectly well

Wednesday 30— All those that I thought had the small pox turned out to be true, the fever left them yesterday, and the disease showed itself. I am perfectly well. . .

Thursday 31 — A young Mandan that died 4 days ago, his wife haveing the disease also — Killed her two children, one a fine Boy of eight years, and the other six , to complete the affair she hung herself
Month of August I bid you farewell with all my heart, after running twenty hair breadths escapes, threatened every instant to be all murdered, however it is the wish of humble servant that the Month of September will be More favorable, the Number of Deaths up to the Present is very near five hundred — The Mandans are all cut off, except 23 young and Old Men —

September 1837

Friday 1 — This Morning two dead bodies, wrapped in a White [bison hide], and laid on a raft passed by the Fort, on their way to the regions below, May success attend them. The Rees that are encamped in the Point of Woods below, are moveing up to encamp at the Mandan Corn fields — No doubt with the intention of takeing all from them, as what few Mandans are left are not able to contend with the Rees — Mitchels [a trader] squaw fell to day.

Saturday 2 — . . . but one death to day, although several are sick, those that catch the disease at Present, seldom die. One Fellow that I had numbered with the dead, I saw on horseback to day — he looked more like a ghost than a being —

Sunday 3 — A young Mandan came to pay us a visit from the Little Village, he informes us, that they are all Most all used up, and that it is his opinion that before the disease stops, that there will not, one be left, except 8 or 10 that has [survived] the sickness —

Monday 4 — a young Mandan that was given over for dead, and abandoned by his Father, and left alone in the bushes to die, came to life again, and is now doing well, he is hunting his Father, with the intent to Kill him, for leaveing him alone. . .

Thursday 7 — The disease not yet over, five and six die off daily. Started the canoe with two Men to Fort Pierre, sent My [son] down with them being afraid of the disease. Several Rees are yet encamped in the Point of Woods below, taken care of the sick, although New Cases every day —Garreau appears much better to day—Bellehumeur's [a fur trader] [Native] Wife and 2 Children has it . . .

Friday 8 — those that are sick in the Fort get worse, there is at present seven sick of the disease. A Son of Old L'etaile died to day — regretted by us all. . .

Sunday 10 — Charboneau arrived late last night from the Gros Ventres, all well in that quarter, the disease has not yet broke out among them, except his squaw, who died 4 days ago —. . . Five More enterments [burials] to day,

Wednesday 13 — A young girl, the daughter of the Old Star, died in the Fort

Thursday 14 —Two Rees that has been with the Sioux since last summer, arrived from their camp on Cannon Ball river, haveing been sent by the Sioux with a Pipe to Make peace with the Rees and Mandans. The disease has not broke out among the [Sioux].

Friday 15 — Two men arrived late last Night in a Canoe from Fort Union. The disease has broke Out at the Assinneboines and Black feet, several had died. . .

Saturday 16 —Two more of Bellehumeurs Children Caught the disease to day, he has at Present his Wife and five children sick —

Tuesday 19 — All quiet to day. . . I was visited by a young fellow from the little Village, he assures Me that there is but 14 of them liveing, the Number of deaths Cannot be less than 800 — . . .

Wednesday 20 — Appearance of rain, cold and Not a stick of Wood in the Fort, all the sick in the Fort 14 in Number, Complains of the Cold last night, haveing passed the Night without fire. Bellehumeurs youngest child died to day —

Friday 22 —. . . Entered into My Winter quarters, My youngest son died to day —

Saturday 23 — An other of Bellehumeurs children died last Night, a fine boy of six years old, sick eight days. . .

Wednesday 27—. . . Charboneau arrived from the Gros Ventres bringing With him 85 Robes . . . reports that but few of the Gros Ventres have the disease and that but 10 has died, the Rees also has it amongst them, and die off 2 and 3 every day — all Peaceable in that quarter, no bad talk against the Whites . . .

Saturday 30 —Two More Rees died to day, with the Small Pox, several More are sick at the Village. All the Rees and Mandans, Men Women and Children, have had the disease, except a few Old Ones, that had it in Old times, it has distroyed seven-eighths of the Mandans and one-half of the Rees Nations, the Rees that are encamped With the Gros Ventres have just Caught it. No doubt but the one-half of them will die also — as they talk of removeing down to this place if so, they Cannot avoid Catching it, as the peste [disease] is at this place.

October 1837

Monday 16 — Several Rees that has been liveing with the Sioux, arrived to day — report that the Small Pox has broke Out amongst them. . .

Why is this important?  The Mandans lost a significant part of their population in 1837. War leaders, spiritual leaders, mothers, fathers, and children died. The tribe was so weakened they could not hunt or harvest their gardens to prepare for winter; they could not defend themselves against attack. Other tribes on the northern Great Plains also suffered terrible losses. Smallpox returned to the Northern Great plains in 1851, again leaving survivors devastated.

Although the traders at Fort Clark and Fort Union knew beyond a doubt that smallpox would have a devastating effect on the Indians of the region, they had few resources with which to slow the outbreak. Had the captain of the St. Peters accepted advice to put the sick man off the boat, the epidemic might have been more limited in its effects. The captain chose to follow his business plan to deliver goods and pick up furs and return quickly to St. Louis. His choice had deadly consequences for his company’s business partners-the people of the northern Great Plains.