The north–south roadway connecting NY 5 in Amherst to the Lake Ontario shoreline in Olcott via Lockport was originally designated as NY 32 in the mid-1920s. In the 1930 renumbering of state highways in New York, NY 32 became part of NY 78, a new route extending from Gainesville in the south to Olcott in the north, mostly along existing but previously unnumbered roads. However, the portion between NY 362 and NY 19 was in the process of being built.Automobile Legal Association (ALA) Automobile Green Book, 1930–31 and 1931–32 editions, (Scarborough Motor Guide Co., Boston, 1930 and 1931). The 1930–31 edition shows New York state routes prior to the 1930 renumbering NY 78's early routing was identical to its modern alignment except from East Aurora to Depew. Initially, NY 78 headed north from East Aurora to Lancaster by way of Maple Street, Jamison and Bowen roads, and Clinton (NY 354) and Aurora streets before following NY 35 west to Transit Road in Depew.
