Michigan Avenue follows the general route of the old Sauk Trail, an important Native American trail. In 1680, the explorer Robert LaSalle was probably the first European to travel along it. During the war of 1812, the U.S. government realized that it needed to create better roads to supply the Western military outposts. The Chicago Road was built in the 1820s and was one of the results of this effort, linking Fort Dearborn in Chicago to Detroit.
In Detroit, Michigan Avenue is one of the major roads and still links the western suburbs and Ann Arbor to downtown. The road continues west and eventually traverses Indiana, Illinois, Wisconsin, Minnesota, South Dakota, North Dakota and Montana. It eventually ends at the Pacific Ocean in Aberdeen, Washington – a total length of 2,484 miles, 210 of which are in Michigan.