In pictures: The history of US Steel

A man in a crane charges slabs of iron at the Gary Works plant in Gary, Indiana, in 1945. Gary Works, US Steel's largest manufacturing plant, was the largest steel mill in the world for most of the 20th century, according to the Chicago Sun-Times.

A group of workers from US Steel attend an English class in Pittsburgh in 1913. The Pittsburgh-based company formed in 1901 as a merger of the nation's leading steel companies, including Carnegie Steel Corp.

Workers strike outside the US Steel plant in Gary, Indiana, in 1919.

An open hearth furnace is seen at a US Steel plant in Duquesne, Pennsylvania, in 1936.

The San Francisco-Oakland Bay Bridge is constructed in California in 1936. It is one of many famous structures that US Steel supplied steel for and erected.

During World War II, US Steel played a critical role in the Allied forces' war efforts. Here, Irma Engstom operates a punch machine in Gary, Indiana, that cut steel discs for 75mm shell cases.

An electric furnace is tilted to pour 40 tons of stainless steel at a plant in Pennsylvania in 1945.

Striking steelworkers picket in Homestead, Pennsylvania, in 1946. An estimated 750,000 workers took part in the walkout, shutting down 1,200 plants in 30 states.

US War Secretary Robert P. Patterson, left, congratulates US Steel President Benjamin Fairless after he was awarded the Medal of Merit in 1946. At right is Gen. Dwight D. Eisenhower, who would later become president.

At left, steel beams for the United Nations Secretariat Building are loaded at a US Steel plant in Munhall, Pennsylvania, in 1948. On the right, a woman knits from a fire escape in New York as the Secretariat Building is under construction.

Workers wash off pulverized coal before forging a steel plate at a plant in South Charleston, West Virginia, in 1950.

A temporary television antenna is adjusted atop New York's Empire State Building by a worker from US Steel's American Bridge Co. in 1950.

A US Steel worker poses for a portrait circa 1951.

A worker oversees pipe production at a plant in Fairless Hills, Pennsylvania, circa 1955.

New twin blast furnaces operate at US Steel's South Chicago Works in 1956. They were among the world's largest at the time, standing 235 feet tall.

A tavern sign tries to entice striking steelworkers in Chicago in 1959.

Workers toil around the clock to complete the installation of the main support cables of the Verrazzano-Narrows Bridge in New York in 1963.

Men work at the Homestead Steel Works factory in Homestead, Pennsylvania, circa 1970. From its peak in the 1950s, the company began to fall behind upstart competitors both foreign and domestic. Competitors in Japan and Germany, which were forced to rebuild from scratch after World War II, used new technologies that required far less labor and energy.

A helicopter lifts a panel of steel over the Louisiana Superdome that was being built in New Orleans in 1973.

A worker helps construct the top floors of the Sears Tower building in Chicago in 1973.

Bob Simmons monitors controls for a furnace and rolling machine at a US Steel research and development facility in Monroeville, Pennsylvania, in 2005.

A man arrives at a US Steel plant in Clairton, Pennsylvania, in 2018. In recent years, US Steel has fallen far below other American steel companies in steel output and stock market value.

President Donald Trump speaks to steelworkers in Granite City, Illinois, in 2018. Trump's administration imposed a 25% tariff on steel imports and 10% tariff on aluminum to shore up the struggling industries.

Steelworker Amanda Menendez watches the steel production process from office monitors in Granite City, Illinois, in 2018.

The US Steel plant in Clairton, Pennsylvania, is seen along the banks of the Monongahela River in 2023.