What did Andrew carnegie do whit his wealth?

Andrew Carnegie used his wealth primarily for philanthropy, believing in the responsibility of the wealthy to give back to society. He funded the establishment of libraries, schools, and universities, and his most notable contributions include the creation of the Carnegie Corporation and the Carnegie Endowment for International Peace. Carnegie famously articulated his philosophy in "The Gospel of Wealth," advocating for the rich to use their fortunes for the greater good of humanity. Ultimately, he donated over 90% of his fortune to various charitable causes.