"The war began in May 1763 when Native Americans, offended by the policies of British General Jeffrey Amherst, attacked a number of British forts and settlements. Eight forts were destroyed, and hundreds of colonists were killed or captured, with many more fleeing the region. Hostilities came to an end after British Army expeditions in 1764 led to peace negotiations over the next two years. Native Americans were unable to drive away the British, but the uprising prompted the British government to modify the policies that had provoked the conflict.Pontiac's War - Wikipedia, the free encyclopedia
Warfare on the North American frontier was brutal, and the killing of prisoners, the targeting of civilians, and other atrocities were widespread. In what is now perhaps the best-known incident of the war, British officers at Fort Pitt attempted to infect the besieging Native Americans with smallpox using blankets that had been exposed to the virus...
...Colonists in western Pennsylvania fled to the safety of Fort Pitt after the outbreak of the war. Nearly 550 people crowded inside, including more than 200 women and children. Simeon Ecuyer, the Swiss-born British officer in command, wrote that "We are so crowded in the fort that I fear disease…; the smallpox is among us." Fort Pitt was attacked on June 22, 1763, primarily by Delawares. Too strong to be taken by force, the fort was kept under siege throughout July. Meanwhile, Delaware and Shawnee war parties raided deep into Pennsylvania, taking captives and killing unknown numbers of settlers in scattered farms...
...Bouquet agreed, replying to Amherst on July 13: "I will try to inoculate the *******s with some blankets that may fall into their hands, and take care not to get the disease myself." Amherst responded on July 16: "You will do well to inoculate the Indians by means of blankets, as well as every other method that can serve to extirpate this execrable race."
Officers at the besieged Fort Pitt had already attempted to do what Amherst and Bouquet were discussing, apparently on their own initiative. During a parley at Fort Pitt on June 24, 1763, Ecuyer gave Delaware representatives two blankets and a handkerchief that had been exposed to smallpox, hoping to spread the disease to the Native Americans in order to end the siege. William Trent, the militia commander, left records that showed the purpose of giving the blankets was "to Convey the Smallpox to the Indians."
It is uncertain whether this fully documented attempt to spread smallpox to the Native Americans was successful. Because many Native Americans died from smallpox during Pontiac's Rebellion, historian Francis Jennings concluded that the attempt was "unquestionably effective". But, some subsequent scholars have raised doubts about whether the smallpox outbreak can be traced to blankets from Fort Pitt with certainty."
An accusation was made that it was done during the 1800s, but I believe the evidence is scanty. Smallpox was common among whites at the time, and it often was transmitted without any conscious effort.
I suspect many of us, crowded into a fort under siege with our deaths likely, might well have endorsed such a plan.