In 1701, Iron Hill was included in the 30,000-acre Welsh Tract, granted by William Penn to a group of settlers fleeing religious persecution in Wales. The Welsh settlers were familiar with ironworking and mining techniques, and soon commenced open-pit mining operations on Iron Hill.
Mining on Iron Hill continued until the late 19th century, though extraction of the low-grade ore proved minimally profitable and many of the ventures ended in bankruptcy. The last mining operation on Iron Hill was run by J.P. Whitaker, who shipped the ore to Principio Furnace in Maryland for smelting.
African-American mine workers and their descendants continued to inhabit the area and, in 1923, Pierre S. du Pont funded the construction of Iron Hill School No. 112C to serve this population. The school remained in operation until Delaware public schools were desegregated in 1965.
Much of the hill is now a wooded recreation area, Iron Hill Park.
Iron Hill School Number 112C was placed on the National Register of Historic Places in 1995.