Built in 1837, the Illinois Iron Furnace was one of only two iron furnaces in the Shawnee Hills of southern Illinois and used a charcoal-blast method to produce high-quality iron that brought the highest market price. Although iron was urgently needed during the Civil War, a lack of workers forced the furnace to close in 1861. It resumed operation in 1872 but was used only sporadically. As iron production techniques advanced and richer ore fields were discovered in the Great Lakes Region, operation became unprofitable, and the last furnace fires died in 1883. Rebuilt and enlarged in 1856, the furnace reached 32 feet in height. The original furnace was partially dismantled in the 1930s to provide rock for the embankments of the Hog Thief Creek Bridge, and the present structure is a reconstruction built in 1967, solid and filled with rubble and concrete. It became part of the Shawnee National Forest in 1950, and in 1973 it was placed on the National Register of Historic Places.