• 1941 - 1990
• 1993 - 2000
• From 2001

» 1941 - 1990

1941 – On April 9, president Getúlio Vargas signs the decree creating Companhia Siderúrgica Nacional. This is ten years after the creation of the Military Commission for Metallurgical Studies.

1946 – The No. 1 Furnace is lit and the mill is officially inaugurated. The mill receives the name Usina Presidente Vargas in 1961. The same year the mines Casa de Pedra in Congonhas, Minas Gerais, and Arcos, in the town of Arcos, also in Minas Gerais, are incorporated by CSN, ensuring self-sufficiency in iron ore, limestone and dolomite for the company.

1954 – The second stage of expansion, with production reaching 680,000 tons per year. Production increases to 1 million and later to 1.3 million tons per year in 1960 and 1963, respectively. In 1960, a private pension fund, CBS Previdência is founded, as well as the CSN Foundation, the social arm of CSN, responsible for promoting citizenship in the communities in which the company operates. Originally dedicated to maintaining the School Technique in the state of Minas Gerais, the by-laws of the Foundation were revised in 1998, and its name and objectives were modified.

1974 – From this year on, installed capacity undergoes further expansion, reaching 1.7 million tons/year, 2.5 millions tons/year in 1977, and 4.6 million tons/year in 1989, with the inauguration of a third furnace.

1990 – I New processes permitting significant gains in sheet metal production are installed. At 1 million tons/year, CSN becomes the largest producer in this segment at a single site. The same year, the Federal Government decides to privatize a number of companies, including CSN, which initiates a restructuring and streamlining process in preparation for its sale.

» 1993 - 2000

1993 – A CSN is sold off at successive auctions on the Rio de Janeiro stock exchange. The government puts the 91% of the shares it held in the company up for sale and control of the company goes to one of the existing shareholders. A period of heavy investment to improve product quality and productivity begins.
The company issues level 1 ADRs (American Depositary Receipts) (over the counter market) on the New York stock exchange (NYSE).

1996 – The company extends its activities in the infrastructure sector, with shares in two new hydroelectric power station projects and the port of Sepetiba, in Itaguaí, in the state of Rio de Janeiro, and the railroad, Ferrovia MRS, integrating their operations.

1997 – Company shares are listed at level II on the New York Stock Exchange (NYSE). Steel production reaches the record level of 100 million tons during the company's little more than fifty years of existence.

1998 - CSN acquires INAL and Intermesa, an important steel distributor based in Rio de Janeiro. The unification of the two operations leads to the creation of the new INAL, a subsidiary of the CSN group.

1999 – Inauguration of the thermoelectric facility at the Usina Presidente Vargas (Volta Redonda, Rio de Janeiro), which in addition to supplying 60% of the company's needs, is environmentally friendly.

2000 – Inauguration of the Itá hydroelectric power station in Santa Catarina, making the company completely self-sufficient in energy. The company also launches the Tecon container terminal, in association with the Companhia Vale do Rio Doce, in the port of Sepetiba. The same year, the company undergoes legal restructuring, with the separation of its shares from those of the Companhia Vale do Rio Doce. Vicunha Siderurgia increases its share in CSN from 14.1% to 46.5%, becoming the majority shareholder. CSN sells off its shares in the company Light.

» From 2001

2001 – CSN acquires the right to purchase the assets of the bankrupt American company Heartland Steel, constituting CSN LLC, the beginning of the internationalization of its interests.
The same year, CSN obtains ISO 14001 certification.
Furnace nº 3 and the Hot Strip Rolling Facility are remodeled, boosting nominal production capacity to 5.8 million tons of bulk steel and 5.1 million tons of rolled products.

2002 – CSN acquires Metalic, a two-piece metal can manufacturer located on the outskirts of Fortaleza, Ceará, becoming the only company in Latin America to make this high technology product.

2003 – As a result of ongoing investments and productivity gains, CSN reaches a production level of 5.3 million tons. Inauguration of the new galvanization line, CSN Paraná, dedicated to the production of coated and pre-painted steels and galvanized aluminum.
The company acquires a 50% share in the Portuguese company Lusosider and control of CSN LLC.
The shared CSN and CVRD logistics operations are separated. CSN now owns 100% of the container terminal at the Port of Sepetiba (TECON), a 49.9% interest in Companhia Ferroviária do Nordeste, and sells off its share in Ferrovia Centro-Atlântica (FCA).

2004 – CSN acquires the remaining 50% of the shares of GalvaSud, in Porto Real, Rio de Janeiro, which becomes a wholly owned subsidiary.

2005 – CSN acquired 100% stocks of ERSA - Estanhos de Rondônia S.A., a company composed by a mine of tin and a foundry of metal tin. Both are located at Rondonia state.

CSN acquired 50% residual stocks of Lusosider, located in Portugal and became the only owner of the company.

2006 – CSN acquired Prada, the bigger manufacturer of steel package to chemical and alimentary industries in the country, with four manufacture units: São Paulo, Araçatuba, Gaspar and Uberlandia.