By 1947, the route had been extended in both directions.
By the next year, the route was extended to its current length.
In both 1935 and 1938 the route was extended east.
In 1959, this route was extended northeast another 7.0 miles.
By 1958 the route was extended north to Highway 63.
The route was extended to its current end at Bus.
The route was extended several times and has been on its current alignment since 1977.
The route was extended to the Indiana state line in 1926.
In 1940, the route was extended to its current length.
By the mid-1970s, the route had been extended north to meet with the newly opened Highway 417.