Between 1775 and 1782 (the years of the American Revolution) a smallpox epidemic spread across North America. By 1782, the disease had reached the villages of the Mandans and Hidatsas. The death rate was very high. The Dakotas attacked the weakened Mandan villages including On-a-slant village (today the villiage is in Fort Lincoln State Park) and Double Ditch village. By 1790, the survivors (of both disease and war) left the Heart River area and moved north to establish villages near Painted Woods Creek and at the mouth of the Knife River. The Mandans who had once occupied six large villages now lived in two small villages. There were only two remaining Hidatsa villages and another village where both Mandans and Hidatsas lived. The populations of the two tribes had been reduced by 75 percent.
The Mandans and Hidatsas also suffered cultural losses because of the smallpox outbreaks. The Mandan villages had always shared some common cultural traits, but each village had a slightly different language. As the survivors were forced to move together for security, the differences disappeared. There were similar cultural losses for the Hidatsas.
The Arikaras who lived farther south along the Missouri River also experienced the smallpox epidemic. By 1790, the Arikaras had been reduced from a large population living in 32 villages to a group that occupied two villages. Only 500 men of military age remained of the 4,000 Arikara warriors who had protected their villages in previous decades.
In 1801, smallpox struck the people of the northern Great Plains again. This time, the epidemic killed fewer people. It is possible that the survivors of the 1782 epidemic were still immune to the virus this time.
In 1830, the Army identified smallpox as a dangerous disease at Indian agencies on the lower Missouri River (in modern-day Missouri, Kansas, and Nebraska). The Secretary of War, L. G. Randolph, authorized Indian agents to hire doctors to vaccinate American Indians living at the agencies. However, these agents were not ordered to vaccinate Indians. Many mothers feared the vaccine. They had seen many babies become sick because doctors did not use sterile procedures (which were unknown at the time). Sometimes vaccine was not effective and the children became sick anyway. For a variety of reasons, the Army’s vaccination campaign did little to stop smallpox epidemics among the Indians of the frontier.
Indian agents on the frontier were concerned about smallpox. Non-Indian settlers were approaching the lands where the tribes lived. Disease was spreading and the agents begged the Office of Indian Affairs (part of the War Department) to provide vaccine for Indians. Finally, in 1832, Congress passed the Indian Vaccination Act. The bill appropriated $12,000 to purchase vaccine and hire doctors to vaccinate Indians. Exactly which tribes would be vaccinated was not specified in the bill. Secretary of War Lewis Cass, who administered the program, decided that the vaccination program would be extended to tribes that were friendly to the United States, those with important economic roles, and those tribes (Cherokee, Choctaw, Chickasaw, Creek, and Seminole) that were being forced out of southern states to relocation sites in the West.
Cass specifically excluded the Mandans, Hidatsas, and Arikaras (along with other tribes living farther up the river) from the vaccination program. Cass believed the fur trade on the Upper Missouri River was no longer economically important. He also stated that the treaties that all three tribes signed in 1825 identified them as hostile towards the U. S. and its citizens. (See Document 1.) Other tribes, including the Teton Sioux (Lakotas) did not have such statements in their treaties. Cass excluded the Upper Missouri tribes from vaccination because he considered them to be far removed (both geographically and socially) from “civilized man.”
Document 1. Preamble to 1825 United States-Mandan Treaty
WHEREAS acts of hostility have been committed by some restless men of the Mandan Tribe of Indians, upon some of the citizens of the United States: Therefore, to put a stop to any further outrages of the sort; and to establish a more friendly understanding between the United States and the said Mandan Tribe, the President of the United States, by Henry Atkinson, Brigadier General of the United States, Army, and Major Benjamin O'Fallon, Indian Agent, Commissioners duly appointed and commissioned to treat with the Indian Tribes beyond the Mississippi river, forgive the offences which have been committed; the Chiefs and Warriors having first made satisfactory explanations touching the same. And, for the purpose of removing all future cause of misunderstanding as respects trade and friendly intercourse between the parties, the above named Commissioners on the part of the United States, and the undersigned Chiefs and Warriors of the Mandan Tribe of Indians on the part of said Tribe, have made and entered into the following articles and conditions, which, when ratified by the President of the United States, by and with the advice and consent of the Senate, shall be binding on both parties . . .
By February 1, 1833, more than 17,000 Indians living along the frontier had been vaccinated against smallpox. Regional Indian agent, J. Dougherty, wanted the program extended to the Upper Missouri in 1833, but his request was denied. When smallpox struck the northern Great Plains in 1837, tribes south of the Mandan villages were fairly well protected. The Mandans, Hidatsas, and Arikaras and other tribes to the north and west suffered horrifying losses from the epidemic.
In 1838, Superintendent of Indian Affairs William Clark requested that vaccines be taken to the Upper Missouri and $5,000 was added to the program. The vaccine provided some protection, but vaccination came too late for thousands of Indian men, women, and children.
Why is this important? In the 18th century, the Indians of the northern Great Plains were experiencing great change. Many tribes had acquired horses. Some tribes were engaged in the fur trade. Horses might have helped nomadic tribes avoid the worst aspects of epidemics because they lived in small mobile groups instead of densely populated villages. Others argue that the horse made all the tribes of the northern Great Plains more mobile and therefore more likely to encounter smallpox. The fur trade increased the opportunities for disease to spread to more people.
Sedentary tribes living near the increasingly busy traffic of the Missouri River were more likely to encounter the smallpox virus than those tribes that lived far from the river. Smallpox epidemics disturbed the cultural patterns of the people of the Upper Missouri. With a fraction of their former population, tribes were forced to relocate after an epidemic. Deadly diseases also upset the balance of power among the tribes, leaving the sedentary tribes more vulnerable to attack by larger tribes.
The Indian Vaccination Act of 1832 was passed Congress by a strong margin. Many who voted for it had the best intentions of preventing death among the Indian tribes. However, Secretary of War Lewis Cass let personal prejudices interfere with the administration of the bill. His callous exclusion of the Upper Missouri tribes led to the deaths of thousands of people a few years later.