Mostly gone now, the Campbell Works of the Youngstown Sheet and Tube Company were once extensive, with 4 blast furnaces, 12 open hearth furnaces, and 381 coke ovens. For more than half a century, Youngstown Sheet and Tube was the dominant steel company in the Mahoning Valley, and one of the largest steel companies in the nation, with two more large plants near Chicago. A number of other former steel mills in the Mahoning Valley have buildings that are still used as steel finishing plants, and some that make steel from scrap.