Carnegie Steel Company, founded in the late 19th century by industrialist Andrew Carnegie, was a pivotal force in the American steel industry and a key driver of the nation’s industrial revolution. Headquartered in Pittsburgh, Pennsylvania, Carnegie Steel revolutionized steel production through the adoption of the Bessemer process, enabling mass production at unprecedented scale and efficiency. By combining vertical integration with technological innovation, the company became the largest and most profitable steel manufacturer in the world. Carnegie Steel not only helped build America’s railways, bridges, and skyscrapers but also laid the groundwork for modern industrial practices. In 1901, the company was sold to J.P. Morgan, forming the U.S. Steel Corporation—the first billion-dollar corporation in American history.