Pontiac's War defeated them at the Battle of Bloody Run on July 31, 1763. Nevertheless, the situation at Fort Detroit remained a stalemate, and Pontiac's influence among his followers began to wane. Groups of Native Americans began to abandon the siege, some of them making peace with the British before departing. On October 31, 1763, finally convinced that the French in Illinois would not come to his aid at Detroit, Pontiac lifted the siege and removed to the Maumee River, where he continued his efforts to rally resistance against the British. Before other British outposts had learned about Pontiac's siege at Detroit,
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