Smallpox had already impacted the Natives of the Northern Plains by the time the Corps of Discovery paddled, poled and sailed their way up the Missouri River in 1804. With no natural resistance to European diseases, many native tribes had been severely reduced in 1780 and ‘81. With this knowledge and undoubtedly with the encouragement of President Thomas Jefferson, Meriwether Lewis included in his traveling medicine kit the vaccine which could have altered the course of history.
But before Lewis and Clark met their first Indians the vaccine went bad, and they didn’t vaccinate a single person.*
In the ensuing years the disease decimated tribe after tribe. In 1832 the artist George Catlin had counted nearly 2,000 Hidatsas and 1,500 Mandans in several villages near present-day Bismarck, North Dakota. But following the 1837 smallpox epidemic which swept across the Plains, their numbers were reduced to 500 and 150 respectively, forcing them to combine forces for mutual protection.
The nomadic tribes, including the sometime ally of the Mandan/Hidatsa, the Arikara, escaped such drastic reductions, but they too suffered sizeable losses.
Ironically, the more sedentary tribes – who were inclined to look more favorably on a relationship with white intruders – were most vulnerable to the disease. The village Indians instinctively pulled together when a family member became ill, thus spreading the highly contagious killer rapidly. The lifestyle of the more warlike nomadic tribes, including the Teton Sioux, who gave Lewis & Clark so much trouble, kept the disease at bay.
It was rumored that more than a few whites, including government officials, noted the demographic changes among these obstacles to “civilization” and abetted the process by selling infected blankets to the unsuspecting Natives.
Whether it was naturally spread or diabolically encouraged, smallpox was a determining factor in the exploration and settling of the West.
But it didn’t have to happen that way.
What if their vaccine had retained its potency and Lewis & Clark had successfully vaccinated the Natives they encountered along the Missouri River and the Upper Plains on their journey to the West?
* Interestingly, no member of the Corps had been vaccinated.