The Belmont Branch was built by the Saint Louis, Iron Mountain and Southern Railroad in attempt to connect the town of Bismark, and its adjacent towns, with important markets east of the Mississippi River. The line was built in 1869 from the StLIM&S mainline at Bismark southeasterly to Belmont, 120 miles away, where a ferry connected the StLIM&S on the west side of the Mississippi River with the Mobile & Ohio Railroad on the east side. In addition, the railway also played an important role in developing local mining and lumber industries along its length. Fredericktown served as the home of the StLIM&S's division point and maintenance shops.

In 1915, the StLIM&S fell into receivership, and was merged into Jay Gould's Missouri Pacific Railroad in 1917. At this time, passenger service along the line ceased, and the MP continued freight service only.

The line was abandoned in two different segments; the northern half was abandoned in 1972, and the southern half in 1984. A small portion of the line was used between Delta and Allenville for a short while, but it too has been abandoned as well.

KMZ: Robert Barnes has made available a Google Earth KML file showing landmarks of bridges, grade crossings and other evidence of this line between Whitewater and Charleston. You can download it here (right-click and Save As...).