New-age billionaires are ushering in their own brand of philanthropy

The Gates's efforts are sprawling, spanning the globe and crossing fields

Step aside, Rockefeller. Move over, Carnegie. Out of the way, Ford.

For the better part of a century, a few Gilded Age names dominated the ranks of big philanthropy.

No longer.

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 cheques. And they are increasingly willing to take on hot-button social and political