The loosely associated settlers in the Clear Fork Valley of the Trinity River, an area known as Medera, were brought together when the Texas & Pacific Railroad brought a line through in 1879 to connect Ft. Worth and Weatherford. A coal and water refueling station was the first stop in Parker County for west-bound trains and it became known as Parker Station. However, when mail marked "Parker County" found its way out of the mail car at "Parker Station", the U.S. Post Office directed the smaller community to find a distinct name. So the community was named in 1882 for the home town of a railroad official from Aledo, Illinois.

The original town site platted by the T.P.R.R. has changed a little over the years. The state highway rounded off a corner or two on it's way through town, and the old depot was moved a couple of hundred yards west and turned into a storage building. The old city well is just a spot in the pavement that won't stay fixed.