Diane Hendricks

Female

White

Coarse public-record coding; race is a noisy, interpretive category.

European American; specific national-origin ancestry not documented

Born Smith, raised in a Wisconsin dairy-farming family. No source found documents a more specific ancestry (e.g. German, Norwegian, English); coded at the broad regional level rather than guessed.

Multi-generational American farm family; no immigration history is documented for either parent.

not established

Not established in the public record.

No move was made for a partner's career.

She and Ken Hendricks were both already in the Janesville/Beloit area when they met and married; no documented move subordinated to his career.

not established

No documented family wealth or property to fall back on. A working dairy-farm family of eleven with no reported savings cushion.

Her own real estate sales commissions and Ken Hendricks's roofing income supported the household through the 1970s while they built up a residential and industrial rental-property business ahead of founding ABC Supply in 1982.

The hardship was imposed, not chosen. There was nothing to fall back on.

The dairy-farm poverty of her childhood and the teenage factory-line period are not framed anywhere as a chosen austerity against a standing family cushion; nothing suggests a soft option was available and declined.

Dairy farmers near Osseo, Wisconsin.

A parent worked for themselves, the strongest known predictor of founding.

Farming is a self-employed trade; not explicitly labeled as such in the source.

8

She has said on the record, "I'm one of nine sisters" — nine daughters total, no sons documented. Figure traced to a single detailed source; other summaries repeat it without independent sourcing.

Her husband and ABC Supply co-founder, Ken Hendricks, died on December 21, 2007, after falling through an unfinished floor at their Afton, Wisconsin home. She has spoken publicly about taking over as chair and continuing to run the company afterward rather than stepping back or selling.

Rural dairy-farming area near Osseo/Mondovi, Wisconsin.

Public rural high school — Osseo-Fairchild High School, graduated 1965.

Moved from the Osseo/Mondovi farm area to the Janesville/Beloit area of southern Wisconsin in her late teens and twenties for factory work and then a real estate career.

She has said her father did not allow his daughters to do farm labor — he hired young men for that work and had the nine girls do housework instead — and has framed leaving the farm for city work and a suit-and-car life as a goal she held from childhood.

Ken Hendricks, a roofing contractor she met while selling custom-built homes around Janesville/Beloit in the mid-1970s. The relationship became a business partnership as much as a marriage.

Ken Hendricks's prior roofing-contracting business and Diane Hendricks's real estate sales and property-rental business, both built through the 1970s, supplied the industry knowledge, contractor relationships, and credit base used to found ABC Supply in 1982.

Skill, Network, Capital

Ken Hendricks, her husband, a roofing contractor who had already built and given away one large roofing operation before they founded ABC Supply together in 1982.

21

Age she earned her real estate broker's license, her first professional-field entry.

14

From the real estate license (roughly 1968) to ABC Supply's 1982 founding.

2

Parker Pen Company as a teenager, then a real estate brokerage, before she and Ken Hendricks went independent. Exact brokerage employer not named in sources reviewed.

High school diploma (Osseo-Fairchild High School, 1965); no college attended. Earned a Wisconsin real estate broker's license at 21.

Wisconsin real estate broker's license, obtained at age 21.

No college. Direct to workforce after high school, then a licensing exam for real estate rather than a degree.

The couple used their own credit lines to secure a bank loan and bought three failing Bird & Sons branches in 1982 to found ABC Supply. No family loan or outside investor is documented.

not established

No family financial transfer is documented for the 1982 founding.

not established

No inheritance is documented at any point in the record reviewed.

It paid its own way from the start. Revenue came before any outside money.

A bank loan secured against the couple's own credit and the assets built through their 1970s real estate and roofing businesses — not a family loan, co-signer, or outside investor.

Founding capital traces to income and assets the couple accumulated over roughly seven years of real estate investment and roofing contracting, not to family wealth.

Grown almost entirely through acquisition debt and reinvested operating cash flow. Remained privately held by the Hendricks family throughout; the two largest acquisitions (Bradco Supply, 2010; L&W Supply, 2016) were also debt-financed rather than funded by outside equity.

Profits after 2007 were reinvested into further acquisitions rather than extracted, most notably Bradco Supply (2010) and L&W Supply (2016).

ABC Supply owns and operates its own distribution branch network — more than 900 locations as of 2025 — rather than franchising or renting access through partners.

A vertical extension of an industry the couple already worked in — Ken Hendricks's roofing-contracting background combined with their existing property-investment business — rather than an outside market observation.

As sole owner and chair since 2007, she holds both full economic ownership and full voting control of a private company — there is no separation between the two, unlike founders who take outside capital and retain only voting control through a special share class.

0

Ken Hendricks had built a large roofing operation before 1982 and gave it to employees to pursue other interests — a deliberate handoff, not a documented failure. No failed prior venture is documented for either of them.

60

Age at Ken Hendricks's death in December 2007, when she became sole owner and chair.

Multi-decade growth in US housing and construction, and a long consolidation of building-materials distribution into a small number of national roll-up players, which ABC Supply rode through serial acquisition from 1982 onward.

Beloit/Afton, Rock County, Wisconsin — where the company stayed headquartered throughout.

Both. ABC Supply itself was founded by buying three failing Bird & Sons branches in 1982 rather than starting from zero, and it grew afterward almost entirely by acquiring competitors — including Bradco Supply (2010) and L&W Supply (2016) — rather than by opening new locations organically.

35

Age at ABC Supply's 1982 founding.

44

From the 1982 founding to 2026; the company is still operating and still hers.

Wholesale distribution of roofing, siding, windows, and building products

23600000000

Forbes real-time estimate, September 27, 2026. ABC Supply is privately held, so this is a journalistic estimate of paper equity value in an unlisted company, not a filing-derived figure. Forbes has reported figures ranging roughly $2.8B (2012) to $21.9B (Dec. 2024) to $23.6B (Sept. 2026) as the company grew and estimation methods were updated; band this, don't treat it as precise.

Journalistic estimate

2026

Nearly all of her wealth is equity in ABC Supply, a private company she owns outright; the Forbes figure is an estimate of paper value, not realized or liquid wealth.

Wealth held in an appreciating, wholly owned private company rather than a salary. ABC Supply itself reported about $20.2 billion in 2025 revenue — that is company revenue, not her personal net worth, which is the figure coded in magnitude above.

Repeatedly named by Forbes as the richest self-made woman in the United States since the late 2010s and ranked on Forbes's list of the wealthiest Americans. Became one of the largest individual donors in Republican politics and funded downtown redevelopment in Beloit, Wisconsin. Subject of the 2025 A&E docuseries "Betting on Beloit."

25

From ABC Supply's 1982 founding to Ken Hendricks's 2007 death and her sole ownership.

Uncapped

Self made, hard-nosed dealmaker, politically influential

Composite of how business and political press have characterized her.

Press

Before

Her reputation as a self-made building-supply operator predates her 2010s emergence as a national-level political donor.

Asset

The reputation accrued from behaviour rather than being manufactured.

Coverage describes her as press-shy rather than as someone who built a public profile deliberately, apart from her political giving.

Splits by political affiliation. Celebrated within Republican political and business circles as a self-made industrialist and top donor; covered more critically elsewhere over the scale of her campaign spending and a January 2011 recording of her urging Governor Scott Walker toward right-to-work legislation.