50. Kluge family
John Kluge amassed his fortune trading broadcast and cellular properties; notable wins included a $2 billion sale of Metromedia TV stations to News Corp and Hearst in 1985, and a $1.3 billion cash-out for Metromedia’s stake in phone company WorldCom in 1995. Upon Kluge’s death in 2010, he gave $400 million to fund financial aid at Columbia University. His son, John Kluge Jr., is also a Columbia graduate and active philanthropist; his angel investment firm, Eirene, is focused on solving sanitation issues through its Toilet Hackers program. His siblings Samantha and Joseph Kluge share the inheritance.