Constructed around 1792, the Joanna Furnace Mansion was the home of the ironmaster and his family. Originally a Federal-style house, it was Victorianized in 1877 by the last ironmaster, L. Heber Smith, and his wife, Ella Jane Grubb Smith, who added a mansard roof, a porte-cochere, and other modern amenities. Oral histories recall a 25-room mansion with 28 fireplaces, polished wood floors, maroon ceilings and walls, wreath sculptures in the parlors, velvet curtains, Persian rugs, bronze sculptures, a grandfather clock, oak furnishings, marble mantles, and gaslight with crystal lamps. Cooks and maids lived in the house, and during the summer months guests from all over the world stayed there. After L. Heber Smith died in 1898 and Ella Jane died in 1920, the house remained in the family for another 25 years. In 1945 it was sold to William and Elizabeth Phelps, who were distantly related to the Smith family. After a short period of ownership by the Phelps family, Bethlehem Steel Corporation acquired the site, and by 1960 the mansion complex stood vacant and overgrown. Because of safety and tax issues, Bethlehem Steel had the mansion, carriage house, and bank barn torn down. The two-story carriage house had sheltered horses, carriages, sleighs, and tack, while the bank barn, built into a hillside along Furnace Road, housed livestock below and hay, grain, and farm equipment above. The mansion grounds were known for landscaping, terraced gardens, cast iron deer in the front yard, and features including a summer kitchen, grape arbor, and greenhouse.