The enterprise began as the American Iron Company, founded in 1852 by Bernard Lauth and Benjamin Franklin Jones, about 2.5 mi (4.0 km) south of Pittsburgh along the Monongahela River.

[3] The first firm to bear the name of Jones and Laughlin was organized in 1861, and headquartered at Third & Ross in downtown Pittsburgh.

The former Otis Steel company along the Cuyahoga River in Cleveland was purchased in 1942, and then in the mid-1960s, a finishing plant was constructed in Hennepin, Illinois.

[6] In 1937, J&L was the subject of a landmark decision of the Supreme Court, NLRB v. Jones & Laughlin Steel Corp., which upheld the constitutionality of the Wagner Act and the Federal Government's power to regulate labor relations by way of the commerce clause.

The Pittsburgh Technology Center now stands on the north side of the Monongahela River where the blast furnaces once stood and the SouthSide Works, a commercial and residential development, stands on the south side where milling operations occurred.

Mill 19, the last remaining structure from the Hazelwood Plant, is being refurbished to serve as a mixed use development including a robotics lab run by Carnegie Mellon University.

The new furnaces included modern skip hoist and sealing arrangement for material charging, and two were expected to be finished in July 1907.

[19] In June 1907, construction was announced of four new Talbot open hearth furnaces totaling 1,000 tons per day.

[20] Jones & Laughlin Steel Co. is a builder of record for a number of bridges and other structures that are listed on the National Register of Historic Places.