The remainder of the route between Homer and Junction City made up the northern portion of pre-1955 State Route 115, which was added to the system in 1928. Route 115 had a second leg that extended southeast from Homer along the present LA 146 to Vienna in neighboring Lincoln Parish. The portion of the route now followed by LA 9 saw only minor changes prior to the 1955 renumbering, such as the straightening of the two portions heading out of Homer and into Junction City. Sections of the original alignment that have not been abandoned exist today as Lisbon Road in Homer and John Kelly Road in Junction City. The entire route between Homer and Junction City was graveled by 1927. Paving of the route between Homer and Antioch was completed during the early 1940s. The paved highway was extended to Summerfield around 1949 and to Junction City by 1953. Other improvements included a new bridge over Corney Lake in 1953, replacing two shorter spans.