1837 Great Plains smallpox epidemic

The Great Plains
Region
Countries	United States, Canada, Mexico
Coordinates	37°N 97°W / 37°N 97°W / 37; -97Coordinates: 37°N 97°W / 37°N 97°W / 37; -97
Length	3,200 km (1,988 mi)
Width	800 km (497 mi)
Area	1,300,000 km2 (501,933 sq mi)
Approximate extent of the Great Plains
Website: Library of Congress (US)

The 1837 Great Plains smallpox epidemic spanned 1836 through 1840, but reached its height after the spring of 1837 when an American Fur Company steamboat, the S.S. St. Peter, carried infected people and supplies into the Missouri Valley. More than 15,000 Native Americans died along the Missouri River alone, with some tribes becoming nearly extinct. Having witnessed the effects of the epidemic on the Mandan tribe, fur trader Francis Chardon wrote, "the small-pox had never been known in the civilized world, as it had been among the poor Mandans and other Indians. Only twenty-seven Mandans were left to tell the tale." The Commissioner of Indian Affairs in 1839 reported on the casualties: "No attempt has been made to count the victims, nor is it possible to reckon them in any of these tribes with accuracy; it is believed that if the above number (i.e., the number 17,200 for the upper Missouri River Indians) was doubled, the aggregate would not be too large for those who have fallen east of the Rocky Mountains."

Smallpox has afflicted Native Americans since it was carried to the western hemisphere by the Spanish conquerors, with credible accounts of epidemics dating back to at least 1515. The Mandan tribe, also called the People of the Pheasants, had previously experienced a major smallpox epidemic in 1780-81 which severely reduced their numbers down to less than a few thousand. Many other tribes along the Missouri river suffered smallpox epidemics during 1801-02 and 1831. Sporadic efforts were made to promote vaccination among the Native Americans since the turn of the nineteenth century, and a couple years after the Indian Removal Act the U.S. Congress took its first step in 1832 to generate public support for vaccination of the Native Americans. But shortly after passage of this congressional act to extend vaccinations to Indians, Secretary Cass stated that no effort would be made "under any circumstances" to send surgeons to vaccinate Indians up the Missouri River beyond the Arickaree tribe. This Great Plains epidemic spanned thousands of miles, reaching California, the northwestern coast and central Alaska before finally subsiding in 1840.

The S.S. St. Peter steamboat, traveling up the Missouri River to Fort Union from St. Louis, docked at Fort Clark near the two earth-lodge villages of the Mandan people on June 18, 1837. The disease spread to the Mandan people, and was of the most virulent, malignant hemorrhagic form. In July 1837, the Mandan numbered about 2,000; by October that number had dwindled to 23 or 27 survivors by some accounts, 138 by another account. On August 11, Francis Chardon, a trader at Fort Clark, wrote, "I Keep no a/c of the dead, as they die so fast it is impossible," and by the end of the month, "the Mandan are all cut off except twenty-three young and old men."