Diane Marie Hendricks (née Smith)
ABC Supply co-founder and chair; Beloit business base, lives in Afton (raised Osseo)
Net worth
$21.7 billion
September 1, 2026
About
Diane Marie Hendricks co-founded ABC Supply in Beloit in 1982, has chaired the company since 2007, and is the city’s living fortune—Forbes listing her among America’s richest self-made women.
She lives in Afton, between Beloit and Janesville.
She was not born in Beloit. One of nine sisters on a dairy farm in Osseo, she decided at ten she would not marry a farmer. Pregnant at seventeen, she finished Osseo-Fairchild at home, assembled pens at Parker Pen in Janesville, sold custom houses, and in 1975 married Ken Hendricks—a Janesville roofer’s son and high-school dropout already running a five-hundred-man crew. In 1982 they liquidated that firm and bought three failing Bird & Sons yards in Muskegon, Belleville, and Springfield. Headquarters: Beloit. First-year sales were $4.5 million; ABC topped the Inc. 500 in 1986. She ran the books and the bank. He climbed the jobs.
On the night of December 20, 2007, Ken fell through a tarp covering an opening in a subfloor over their Afton garage and died the next morning on a Rockford operating table. Forbes had just listed him at $3.5 billion. Diane kept ABC, bought Bradco in 2010 and L&W Supply in 2016, and grew the firm past nine hundred branches and $20.2 billion in 2025 revenue. She poured millions into the old Fairbanks-Morse floors, put her name on a ballpark, and filmed Betting on Beloit with her daughter. Forbes put her personal fortune at $21.7 billion as of June 3, 2026. The farm was Osseo; the death was Afton; the fortune is Beloit.
Notable facts
She co-founded ABC Supply in Beloit in 1982 and has been chair since 2007; the company reported $20.2 billion in 2025 revenue across more than 900 branches.
Forbes listed her at $21.7 billion as of June 3, 2026, among America’s richest self-made women.
After Ken Hendricks died in December 2007 from a fall at their Afton home, she kept and expanded ABC, acquiring Bradco (2010) and L&W Supply (2016).
What questions can this profile answer
- What makes Diane Marie Hendricks (née Smith) notable?
- Diane Marie Hendricks co-founded ABC Supply in Beloit in 1982, has chaired the company since 2007, and is the city’s living fortune—Forbes listing her among America’s richest self-made women. She lives in Afton, between Beloit and Janesville.
- What is Diane Marie Hendricks (née Smith)'s estimated net worth?
- Diane Marie Hendricks (née Smith)'s estimated net worth is $21.7 billion as of 2026-09-01.