United States Steel Corporation engages in the production and sale of steel mill products in North America and Europe. The company operates in three segments: Flat-rolled Products (Flat-rolled), U. S. Steel Europe (USSE), and Tubular Products (Tubular). The Flat-rolled segment offers slabs, rounds, strip mill plates, sheets, and tin mill products. This segment serves customers in the service center, conversion, transportation, construction, container, appliance, and electrical markets. The USSE segment produces and sells slabs, sheets, strip mill plates, tin mill products, and spiral welded pipes, as well as heating radiators and refractory ceramic materials. This segment serves customers in construction, service center, conversion, container, transportation, appliance and electrical, oil, gas, and petrochemical markets. The Tubular segment produces and sells seamless and electric resistance welded steel casing and tubing; and standard, line pipe, and mechanical tubing products. This segment serves customers in the oil, gas, and petrochemical markets. United States Steel Corporation also provides transportation services, including railroad and barge operations. It also owns, develops, and manages various real estate assets comprising approximately 200,000 acres of surface rights primarily in Alabama, Illinois, Maryland, Michigan, Minnesota, and Pennsylvania, as well as approximately 4,000 acres of land in Ontario, Canada. The company was founded in 1901 and is headquartered in Pittsburgh, Pennsylvania.