Formed by July 1, 1919, M-28 began in Wakefield at a junction with then M-12 and ran roughly along the current alignment to end at M-15, east of Covington. These two termini roughly correspond to the modern US 2 and western US 41 junctions respectively. M-28 was extended in 1927 along US 41 into Marquette County and east over M-25 through Chatham, Munising, and Newberry, before ending in downtown Sault Ste. Marie. At Negaunee, M-28 took the former routing of M-15 between Negaunee and Marquette for while US 41 ran along a portion of M-35. This southern loop routing of M-28 lasted until approximately 1936, when M-28 was moved to US 41, and the former route became CR 492. A new routing of M-28 in the Newberry area opened later that year, and a new M-28A (later Bus. M-28) existed until 1953. Another realignment in 1937 marked the transfer of M-28 out of downtown Ishpeming and Negaunee. This former routing later became Bus. M-28.