US Steel Corp. agreed to be purchased by Nippon Steel yesterday in an all-cash $14.9B deal, marking a significant move for the Japanese steel giant in the US. The acquisition is set at $55 per share and will assume US Steel’s debt. The merger, if approved, would retain the US headquarters in Pittsburgh. Founded in 1901 by Andrew Carnegie and JP Morgan through the merger of several steel companies, US Steel was once the world's largest company and the first to be valued at over $1B. It fueled America's construction boom, including iconic buildings like Chicago's Willis Tower and the UN building in New York City, but later faced decline. The acquisition would position Nippon as the world’s third-largest steelmaker, after China Baowu Group and Luxembourg-based ArcelorMittal. US Steel rejected a lower price bid earlier this year by rival Cleveland-Cliffs that would have purchased the company at $35 per share. The merger is pending shareholder and regulatory approval and will likely face opposition from US Congress and the United Steelworkers union, who have cited contractual demands for new labor agreements before the sale is final.