T. DENNY SANFORD

Sanford’s First Premier Bank has only 17 branches, but it’s one of the largest issuers of Mastercards in the country, specializing in high-risk borrowers. The Minnesota native started working in his father’s garment shop at age 8. At 18 he was sentenced to 90 days in jail for fighting but was offered a lighter sentence by the judge if he agreed to go to college. Sanford has given away more than $1.6 billion to causes such as healthcare and education.