The American Legion Memorial Highway follows the path of two Native American trails – the Saginaw and the Mackinaw. The road as we know it began in 1913, when the Trunk Highway System was developed by the government. The 5 mile long Mackinaw Bridge is part of the road which stretches from Sault Ste. Marie, Michigan to Miami, Florida – a total of 1,786 miles, 396 of which are in Michigan.