Clockwise from top left, George Soros, Bill Gates, Mark Zuckerberg, Henry Ford, John D. Rockefeller and Andrew Carnegie. : In a matter of years, a new crop of ultra-wealthy Americans has eclipsed the old guard of philanthropic titans. With names like Soros, Gates, Bloomberg, Mercer, Koch and Zuckerberg, these new megadonors are upending long-established norms in the staid world of big philanthropy. They have accumulated vast fortunes early in their lives. They are spending it faster and writing bigger checks.