2. Koch family
Net worth: $89 billion
Source of wealth: Diversified
Koch Industries is now the nation’s second-largest private company, with $115 billion in sales.
3. Mars family
Net worth: $60 billion
Source of wealth: Candy
Mars is largest candy company in the world. The company, founded in 1911 by Frank Mars in Tacoma, Wash., invented M&M candies — more than 400 million are produced each day — along with Snickers, Skittles and the namesake Mars bar. Mars also makes Uncle Ben’s rice and owns pet food brands Pedigree and Whiskas.
4. Cargill-MacMillan family
Net worth: $43 billion
Source of wealth: Cargill Inc.
Cargill is the largest privately held company in the country. It is invested in food, agriculture, financial and industrial products and services on a global scale. So it’s no surprise the six family members who own an estimated 88 percent stake in the company are billionaires.
5. Johnson family
Net worth: $39 billion
Source of wealth: Money management
Edward C. Johnson II founded Fidelity Investments in 1946. His son, Edward “Ned” Johnson III, and his grandchildren own 49 percent of the Boston-based firm, the country’s second largest mutual fund with $1.7 trillion under management.
6. Hearst family
Net worth: $35 billion
Source of wealth: Hearst Corp.
George Hearst acquired the San Francisco Examiner as compensation for a gambling debt. In 1887, George’s son, William Randolph Hearst (the alleged model for “Citizen Kane”), took over the paper. Soon thereafter he purchased the New York Journal and began building a media empire. According to Forbes, The Hearst livery now includes “49 newspapers, nearly 340 magazines around the globe, and valuable stakes in cable TV channels ESPN, Lifetime and A&E.”
7. Cox family
Net worth: $32 billion
Source of wealth: Media
The Cox family, who run an Atlanta-based media empire, are worth an estimated $32 billion, according to Forbes. The holdings include Cox Communications, Cox Media Group, AutoTrader Group and Kelley Blue Book. Anne Cox Chambers is the majority owner, with a 50 percent stake, according to Forbes.
8. Pritzker family
Net worth: $29 billion
Source of wealth: Hotels, investments
Eleven family members make up the Pritzker family, including Commerce Secretary Penny Pritzker. The family is most famous for owning the Hyatt hotel chain.
9. S.C. Johnson family
Net worth: $25.5 billion
Source of wealth: Cleaning products
The Johnson family is a leading maker of household products, including Pledge, Windex, Saran Wrap and, of course, car wax. The company started in 1886 as a small parquet flooring company in Racine, Wis.
10. Duncan family
Net worth: $25.4 billion
Source of wealth: Energy
Born poor in rural Center, Tex., Dan Duncan was raised by his grandmother. He eventually struck it rich in natural gas, oil and petrochemical pipelines.