The entire length of this two-lane highway is part of the former alignment of State Route 15, which was realigned onto a new expressway from Findlay to Carey at that time.

With the completion of a new four-lane divided expressway from Interstate 75 south of Findlay and U.S. Route 23/State Route 103 south of Carey, the State Route 15 designation, which had utilized a two-lane roadway between downtown Findlay and downtown Carey to that point, was transferred onto the new expressway, which parallels the two-lane road to the south.

The route has utilized the same alignment from inception to this day, and has not seen any significant changes since its original designation.

[5] However, within a year, the part west of old U.S. 223 (present day Monroe Street and Alexis Road in Sylvania) was renamed Route 120 due to difference of traffic.

[6] Subsequently only the portion east of Monroe Street remained as Route 568, entirely encompassing Alexis Road.