350. Clayton Mathile
$2.3 billion Self-made Score: & Source: pet food
age: 76 residence: brookville, ohio B.a., ohio northern u. ’62
After a stint as a Campbell Soup accountant, Mathile became employee No. 6 at pet-foods maker Iams in 1970. He bought the company in 1982 and sold it to Procter & Gamble in 1999 for $2.3 billion. He now operates Aileron, which offers management classes at its campus in Tipp City, Ohio. He also invests in tech startups like oovoo, a video-chat app that claims to have 185 million registered users but, according to 3rdparty data, is used by only about 2.5 million a month.