Pontiac (Ottawa leader) exaggerated. Historians today generally view him as an important local leader who influenced a wider movement that he did not command. The war began in May 1763 when Pontiac and 300 followers attempted to take Fort Detroit by surprise. His plan foiled, Pontiac laid siege to the fort, where he was eventually joined by more than 900 warriors from a half-dozen tribes. Meanwhile, messengers spread the word of Pontiac's actions, and the war expanded far beyond Detroit. In July 1763, Pontiac defeated a British detachment at the Battle of Bloody Run, but he was unable to capture the fort. In
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