SH 168 was first proposed on August 4, 1932, traveling from Floresville in Wilson County to SH 81. The proposal was listed as a conditional designation, meaning that it would not be maintained by the State Highway Commission. On January 9, 1933, it was extended to Campbellton in Atascosa County. On February 12, 1934, the portion from Campbellton to Floresville was cancelled and an extension of SH 97 to Floresville was substituted for it. On March 13, 1934, SH 168 was cancelled, as it became part of SH 97. On September 26, 1939, SH 87 was designated to a road that followed the general course of present-day SH 168.
