Pontiac (Ottawa leader) October, he lifted the siege and withdrew to the Illinois Country. Pontiac's actions contributed to the British Crown's issuance of the Proclamation of 1763, which prohibited British settlers west of the Appalachian Mountains. This was an effort to preserve an area for Native Americans. Pontiac's influence declined around Detroit because of the unsuccessful siege, but he gained stature as he continued to encourage resistance against the British. Seeking to end the war, British officials made him the focus of their diplomatic efforts. In July 1766, he made peace with British Superintendent of Indian Affairs Sir William Johnson. The British attention
Siege of Fort Pitt become by 1763 and how far British officers were willing to go in ignoring their own soldiers' code of warfare. A devastating smallpox epidemic plagued Native American tribes in the Ohio Valley and Great Lakes area through 1763 and 1764, but the effectiveness of these instances of efforts to spread smallpox remain unknown. After extensive review of surviving documentary evidence, historian Francis Jennings concluded the attempt at biological warfare was "unquestionably effective at Fort Pitt"; Barbara Mann deduced "it is important to note that the smallpox distribution worked"; Howard Peckham noted the resulting fatal epidemic "certainly affected their vigorous prosecution