Several deck hands had died of smallpox…

Several deck hands had died of smallpox by the time the S.S. St. Peter made it to Fort Union, but only Jacob Halsey, an American Fur Company clerk, showed visible signs of the disease.

In an attempt to stop the spread of the disease fort personnel perform primitive inoculations.

Pus from Halsey's skin eruptions is used to inoculate approximately thirty native women and several white men living in or around the fort.

Within two weeks, the women who have received the inoculations begin dying from the disease.

As the disease reaches a peak at Fort Union bands of natives continue to arrive at the fort for trade.

Halsey wrote: I sent our interpreter to meet them on every occasion, who represented our situation to them and requested them to return immediately from whence they came however all our endeavors proved fruitless, I could not prevent them from camping round the Fort-they have caught the disease, notwithstanding I have never allowed an Indian to enter the Fort, or any communication between them & the Sick; but I presume the air was infected with it for a half mile...

Later, a longboat is sent to Fort McKenzie via the Marias River.