Can you please list which biographies of Carnegie and Rockefeller you recommend ?
There is also this book : The Tycoons: How Andrew Carnegie, John D. Rockefeller, Jay Gould, and J. P. Morgan Invented the American Supereconomy Reprint Edition, Kindle Edition by Charles R. Morris
Links: https://www.amazon.com/Titan-Life-John-Rockefeller-Sr-ebook/...
https://www.amazon.com/Andrew-Carnegie-David-Nasaw-ebook/dp/...
https://www.amazon.com/Tycoons-Carnegie-Rockefeller-Invented...