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Workers at the Cornwall Iron Mines, Lebanon County, PA, 1917.

The charcoal iron industry flourished in Pennsylvania mostly because the Commonwealth had an abundance of four critical resources– iron ore, limestone for flux, water for power, and forests that provided wood for fuel. The nearness of ore deposits dictated, more than anything else, where ironmasters situated charcoal furnaces. Iron ore was the heaviest and thus most expensive resource to transport to furnaces. Limestone and water were common in Pennsylvania. It was only later when furnaces such as Centre Furnace depleted nearby forests that wood cutters had to go far afield and sources of wood became a primary concern. Thus ironmasters concentrated furnaces in places in the state, such as the Juniata Iron region, where they could readily obtain ore.

Cornwall Ore Banks

Ironmasters and workers commonly spoke of "mining" iron ore, but before 1850 it was something of a misnomer to describe this process as "mining." As Johann Schoepf, who traveled Pennsylvania, noted, "Any knowledge of mining is superfluous here, where there is neither shaft nor gallery to be driven, all work being at the surface, or in great, wide trenches or pits." Workers used pickaxes and pry bars to get the ore out of the ground. After digging the ore, they tried to remove as much waste, including clay and soil, as possible from the ore. One method was to "flat" the ore, or roll cast-iron, horse-drawn breakers over the ore. In the nineteenth century workers also often washed the ore to separate waste.

Cornwall Ore Banks, Lebanon, Pa.

Ore in the rich, abundant Cornwall Banks in Lebanon County lay in two deposits. One deposit outcropped and was accessed easily. The top of the second deposit lay 150 feet underground; this deposit was not located until 1919. The first deposit proved to be the most important source of ore for area iron furnaces until the late nineteenth century. Peter Grubb bought this deposit in 1732 and used it to supply iron furnaces that he owned. He located Cornwall Furnace close by to take advantage of this deposit. Others also acquired interests in Cornwall Banks, including Robert Coleman who gained five-sixths ownership by 1798. After Coleman died in 1825, shares in the mines went to multiple owners who competed to dig ore from various areas of the deposit. The competition proved so disputatious that contending owners went to court in 1856 in a drawn-out lawsuit to determine who could mine what ore from the deposit.

Robesonia Cut and Hoist, Cornwall Ore Banks.

 

Cornwall Mines, Lebanon County, PA, circa 1880.

Until the mid-nineteenth century, the multiple owners relied upon the prevalent methods of using pick axes and pry bars to dig ore out of the ground. Miners opened pits or trenches around the deposit. By mid-century, owners increased production by improving the transportation of ore and greatly changing mining techniques. Coleman family interests sponsored the construction of the North Lebanon Railroad during the 1830s to haul ore in railroad cars to the Union Canal, and then expanded the North Lebanon Railroad network to link the ore deposit directly to Coleman-owned iron furnaces.

Iron workers at Cornwall Banks, Lebanon County, PA, circa 1883.

In the 1880s the North Lebanon Railroad connected to the Pennsylvania Railroad, further expanding the market for Cornwall Banks ore. In 1858 bench mining replaced the earlier methods of mining. Miners extracted ore in benches or steps, each sixteen to twenty feet deep, creating one, growing open pit, instead of the earlier, small pits and trenches. During the 1870s steam shovels replaced the hand-loading of railroad cars.

By the late nineteenth century Cornwall Banks developed into the largest, most important iron mine east of the Lake Superior ore deposit. During the 1890s miners excavated 564,000 tons of ore each year on average. Owners continued to improve mining techniques, such as constructing an inclined hoist to haul coal out of the deepening pit.

In 1926 mining began in the second ore deposit, and the Bethlehem Steel Corporation gained sole ownership of both deposits to supply ore to its steel mills. Mining continued until 1973 when Tropical Storm Agnes filled the mine with water. Engineers determined that the value of the remaining ore was not worth the cost of draining the mine. After 234 years of operation and total production of 106 million tons of ore, the Cornwall Banks closed down.

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