Existing from 1926 until the mid-1970s, US-25 connected Port Austin and Port Huron with Detroit and on south through Monroe and into Ohio at Toledo. Today, I-94 and I-75 run along much of the general route followed by US-25 during its existence and the reasons for its "decommissioning" in the 1970s. Please see the Historic US-25 pages for more information on this historic U.S. Highway.
From its debut as one of Michigan's "new" US Highways in 1926, US-27 was not one of the state's major US Highway routings for the first part of its existence. In the 1960s, the route of US-27 gained more prominence as portions of it were "freeway-ized" and portions of the route were designated as parts of two different Interstate corridors. After having its northern end hacked off in the early-1960s, US-27 remained intact until MDOT sought, on two separate occasions in the 1990s, to have the designation completely removed from the state. The department finally succeeded and in 2002, US-27 is relegated to the history books as all portions of the route in the state are decommissioned. Please see the Historic US-27 pages for more information on this historic U.S. Highway.