2020, U.S. Steel announced it would acquire the remaining ownership interest in Big River Steel for $774 million. The acquisition was completed in January 2021. In February 2022, U.S. Steel began construction on a new mill in Osceola, Arkansas which will be operational by 2024. In April 2022, the electric arc furnace flat-rolled Big River Steel mill in Osceola became the first ResponsibleSteel site certified in North America following an independent audit by SRI Quality System Registrar (SRI). Railroad ownership U.S. Steel once owned the Northampton and Bath Railroad. The N&B was an short-line railroad built in 1904 that served Atlas Cement in Northampton, Pennsylvania, and Keystone Cement in Bath, Pennsylvania. By 1979 cement shipments had dropped off such that the railroad was no longer economically viable, and U.S. Steel abandoned the line. A section of track was retained to serve Atlas Cement. The remainder of the right-of-way was transformed into the Nor-Bath Trail. U.S. Steel also owned the Atlantic City Mine Railroad, whose line in Wyoming operated from 1962 until 1983 and served an iron ore mine north of Atlantic City, Wyoming. Through its Transtar subsidiary, U.S. Steel also owned other railroads that served its mines and mills. Those properties included the Duluth, Missabe & Iron Range Railway in the iron-mining region of northeast Minnesota; the Elgin, Joliet & Eastern that served its Gary Works in northwest Indiana; the Birmingham Southern Railroad serving the U.S. Steel mill in Birmingham, Alabama; and the Bessemer & Lake Erie and Union railroads in western Pennsylvania that delivered iron ore and provided plant-switching services at its mill complex in Braddock, Pennsylvania and coke works in Clairton, Pennsylvania. U.S. Steel also owned a large Great Lakes commercial freighter fleet, under the Pittsburgh Steamship Company, that transported its raw materials from the Duluth area to Ashtabula, Ohio; Gary, Indiana; and Conneaut, Ohio. The laker fleet, the B&LE, and the DM&IR were acquired by Canadian National after U.S. Steel sold most of Transtar to that company. The ships are leased out to a different, domestic operator because of the United States cabotage law. Inclusion in the Dow Jones Industrial Average (1901–1991) U.S. Steel is a former Dow Jones Industrial Average component, listed from April 1, 1901, to May 3, 1991. It was removed under its USX Corporation name with Navistar International and Primerica. An original member of the S&P 500 since 1957, U.S. Steel was removed