James Laughlin, one of the founders of Jones & Laughlin, constructed the first Eliza Furnace, a stone blast furnace for smelting iron. Built in 1858 before the Civil War, Eliza marked the city's emerging iron and steel industry and was the first iron furnace built in Pittsburgh since 1794. By Victorian tradition, the furnaces were named after women because they were considered temperamental.
With new technology, Jones & Laughlin rebuilt the Eliza furnace, eventually adding new furnaces.
Molten iron from Eliza was first transported across the river by boat and later by rail cars over the Hot Metal Bridge. There, on the south side of the river, were the Bessemer Converters and open hearths. Steel ingots went back across the river to be rolled or fabricated into sheets, wire, rails, and other products.
Eliza and the other blast furnaces posed an ever-present danger for workers. In 1907, without warning, the No. 2 furnace exploded and burned 14 workers to death.
The tragedy brought steel men from all over the nation to examine Eliza for flaws. None were found.
As Big Steel change, the last Eliza Furnace was shut down on June 22, 1979, and replaced with two electric furnaces across the river on the South Side. These furnaces closed in 1987.