They started as white guys, besides Oprah of course.
EDIT: Perhaps I should have been clearer. Given the average age, they were significantly advantaged by the color of their skin and patriarchal state of society, so they didn't start with "nothing." They took advantage of the many opportunities afforded to white males at the time. I'm not saying they were lazy or don't deserve their wealth, but Bloomberg seems to be painting them in the best possible light.
EDIT: Perhaps I should have been clearer. Given the average age, they were significantly advantaged by the color of their skin and patriarchal state of society, so they didn't start with "nothing." They took advantage of the many opportunities afforded to white males at the time. I'm not saying they were lazy or don't deserve their wealth, but Bloomberg seems to be painting them in the best possible light.