Who made his fortune through the steel industry?

Andrew Carnegie is recognized as a key figure in the steel industry during the late 19th century. He founded Carnegie Steel Company, which became one of the most significant and influential steel producers in the United States. His innovative approach to steel production, particularly through the adoption of the Bessemer process, allowed for the mass production of steel, which was essential for infrastructure development, including railroads, bridges, and buildings. Carnegie's success was not just due to his business acumen but also his focus on efficiency and his ability to vertically integrate his operations by controlling both raw material sources and distribution.

In contrast, John D. Rockefeller is best known for his role in the oil industry through the Standard Oil Company, while J.P. Morgan was a prominent banker and financier who influenced various sectors, including railroads and utilities. Thomas Edison, renowned for his inventions in electricity and technology, did not directly engage in the steel industry. Thus, Andrew Carnegie stands out as the individual who made his fortune specifically through steel production.