It runs from U.S. Route 51 south of Du Quoin to the New Harmony Toll Bridge over the Wabash River to State Road 66 at the Indiana state line.

[1] Illinois 14 runs mostly east–west from Du Quoin to New Harmony, Indiana.

[3] Continuing eastward from McLeansboro, IL 14 then serves the Hamilton County State Fish and Wildlife Area.

[4] It was built as a toll bridge, but has since been closed to automobile traffic since May 21, 2012.

In 1937 it was extended east to its current terminus across from New Harmony, Indiana, replacing Illinois Route 139 in the process.