On this day in 1812, during the War of 1812, the British captured Mackinac Island from the Americans. John Jacob Astor, owner of the American Fur Company, played a pivotal role by alerting British forces at Fort St. Joseph of the outbreak of war, inadvertently aiding in the swift British takeover of Fort Mackinac. This event marked the beginning of British control over Michigan's peninsulas, which would later revert to American sovereignty.