In 1993 Stannard wrote a book called American Holocaust: The Conquest of the New World: Columbus and the Conquest of the New World. In it, Stannard mentions (page 124) the Indian marches where they deliberately took them through diseased areas and fed them rotting food:
Like other government-sponsored Indian death marches, this one intentionally took native men, women, and children through areas where it was known that cholera and other epidemic diseases were raging; the government sponsors of this march, again as with the others, fed the Indians spoiled flour and rancid meat, and they drove the native people on through freezing rain and cold
Unfortunately there are no sources for this claim, so does anyone know if there exist any first hand accounts that they deliberately took the natives through diseased areas and were fed rotten food?
There is evidence to suggest that the Europeans knew these actions would help spread disease amongst the natives because the medical theory at the time, Miasma theory, suggested "epidemics were caused by miasma, emanating from rotting organic matter".
On top of that the Amherst letters provide evidence that the Europeans knew that an increased proximity to a disease like smallpox increased your chances of getting it. As mentioned in the 94th Illinois General Assembly (line 23) they also knew not to march through villages and were given blankets from a hospital where small pox had broken out.