Deeply religious, and yet eminently ruthless, Rockefeller saw his wealth as part of a divine plan. "It has seemed as if I was favored and got increase because the Lord knew that I was going to turn around and give it back," he later said. And he set about giving it away as if it were a religious mission.

In his lifetime—nearly a century —Rockefeller’s massive and unprecedented wealth brought opprobrium and unwanted attention to him and his family. As such, it was something of a burden. And for five generations, the Rockefellers have attempted to lighten the load. While family members have pursued their own interests in business, they have continued to pursue philanthropy together. By creating institutions, hiring people to staff them, and devoting their own lives to charity, they made giving away funds a profession. Philanthropy would become a full-time job for John D. Sr., his son, grandchildren and some of his great- and great-great-grandchildren.