Final answer:
J. Edgar Thomson was the President of the Pennsylvania Railroad and was instrumental in its growth, influencing the American steel industry.
Step-by-step explanation:
The Pennsylvanian J. Edgar Thomson held the prominent position of being the President of the Pennsylvania Railroad from 1852 until his death in 1874. Under his leadership, the Pennsylvania Railroad became the largest company in the world and played a significant role in the growth of the American steel industry. Thomson's success with the railroad led to the naming of the J. Edgar Thomson Steel Works by Andrew Carnegie, who recognized the importance of the industry to the country's future growth.