You should do more research, even your one account doesn’t hold up, and it doesn’t support your initial claim, did you get that from history.com?
Medved examines the evidence and concludes “The endlessly recycled charges of biological warfare rest solely on controversial interpretations of two unconnected and inconclusive incidents 74 years apart.”
The first was in response to Pontiac’s Rebellion (1763), a ferocious small war undertaken by the Great Lakes Indians (who had been allied with the defeated French in the French and Indian War) against British settlements. The Ottawa leader Pontiac told his followers to “exterminate” the whites. They did their best. Hundreds of settlers were tortured, scalped, cannibalized, dismembered, or burned at the stake. As the Indians were besieging Fort Pitt, Field Marshal Lord Jeffery Amherst wrote to a subordinate, “Could it not be contrived to send the Small Pox among the disaffected tribes of Indians?” But nothing seems to have come from this correspondence.
Back in 1957 there were people alive who had direct memory of the plains wars. Indians were in general hated, and the teacher was definitely not fond of Indians.
There were horrendous atrocities committed by both sides, as is usually the case. You would be mistaken to believe white man always waged a clean war.
Thank you for participating this way. It is a lot better than label-making.