Fort Mackinac

Fort Mackinac's commanding position on a 150-foot limestone bluff above the Straits of Mackinac made it one of the most strategically significant posts in the upper Great Lakes. The British constructed the current fortification in 1780 — moving their garrison from the mainland at Fort Michilimackinac to this more defensible island position — and held it for 16 years following the end of the Revolutionary War.

Jay's Treaty of 1794 required British withdrawal from American territory, and the fort was transferred to U.S. forces in 1796. The transfer proved temporary: at the outset of the War of 1812, a British force from St. Joseph Island captured the fort in a pre-dawn surprise attack on July 17, 1812, before American commanders in the region knew war had been declared. The British held it until 1815 under the terms of the Treaty of Ghent.

During the Civil War the War Department converted Fort Mackinac into a military prison for Confederate sympathizers and political detainees, including the mayor of Baltimore and members of the Maryland legislature. The island's physical isolation made escape nearly impossible.

In the final decades of active military occupation, the garrison suffered from recurring disease outbreaks. A typhoid fever epidemic killed several children of soldiers stationed at the fort; the deaths are recorded in post records and the graves of some victims are marked in the post cemetery on the island. The Army decommissioned Fort Mackinac in 1895, after which the State of Michigan assumed management. Mackinac State Historic Parks has operated it continuously as a living-history museum since the twentieth century.