A musket blast, a gastrocutaneous fistula, and research into the physiology of digestion. These all became central components in one of the most famous and influential episodes in the history of American surgery. On June 6, 1822, an illiterate 19-year-old French Canadian hunter named Alexis St Martin (1803?-1880) was wounded in the left side of the upper abdomen by an accidental musket discharge of duckshot, an incident that left him with a permanent gastrocutaneous fistula. The untoward event occurred just outside of Fort Mackinac, Territory of Michigan, an army base where William Beaumont (1785-1853) was stationed as post surgeon. As Beaumont would later relate: