388. J. Joe Ricketts
$2 billion Self-made Score: ) Source: td ameritrade age: 76 residence: little Jackson hole, wyo. B.a., Creighton ’68 It took Ricketts 9 years to graduate from Creighton, as he periodically quit school in order to save up more money for tuition. He worked as a dorm-room janitor to get free room and board. In 1975 Ricketts cofounded First Omaha Securities, which grew into giant discount broker TD Ameritrade. He stepped down from its board in 2011 to focus on other investments and philanthropy; he has donated $40 million to education initiatives for low-income students, including establishing 3 high schools.