Michigan first started converting US 23 into a freeway in 1957. Several years later, the state first proposed a realignment of US 223 in 1965. This change would have rerouted the highway to replace M-151 in southern Monroe County, and use the US 23 freeway to connect to Sylvania, Ohio. The Michigan State Highway Department truncated M-151 in 1965, eliminating the section that ran eastward through Samaria to US 25 south of Monroe. The remainder of the US 223 realignment change was made in 1977 when Michigan shifted its segment of US 223 over M-151 as previously proposed. Instead of running south through Ottawa Lake along Memorial Highway, US 223 continued east to the US 23 freeway and south into Ohio. The former routing has been retained as an unsigned highway.