Final answer:
J.P. Morgan made his fortune by investing wisely through his firm, gaining control over companies’ policies, and stabilizing the financial system during crises. His notable achievements include creating the U.S. Steel Corporation and aiding banks during the Bankers' Panic of 1907.
Step-by-step explanation:
Born into a wealthy family with his father being a London banker, J. Pierpont Morgan rose to prominence in New York after moving in 1857 to oversee the family's business interests. His firm, J. Pierpont Morgan and Company, played a pivotal role in investing family wealth into promising companies, which netted substantial profits.
The company's influence extended beyond investment, securing control over company policies through board seats, and transforming industries through consolidation. One of Morgan's most notable achievements was the creation of the U.S. Steel Corporation by buying out Andrew Carnegie's steel holdings and merging them with other companies.