Diane Hendricks is just about ready to sit down for a video interview when she makes a last-minute dash to her walk-in closet. She returns with a small American flag pin fastened to the lapel of her slimcut black blazer. “I love this country. I’m just so blessed to have been born in America,” she says. “I never had a door that didn’t open for me. I never thought about being a female and not being able to do what I do.”

Her patriotism is on display throughout her 9,500-square-foot southern Wisconsin home. In her office is a statuette of Ronald Reagan on horseback and a photo of her with Donald Trump near a stack of books with titles like “The MAGA Doctrine,” “Land of Hope” and “Back in the Game.” Downstairs is a high-quality numbered print, identical to the one that hung in Trump’s White House, depicting ten Republican presidents drinking at a fictional gathering (Dwight Eisenhower seems to be enjoying his Scotch; teetotaling Trump nurses a Diet Coke). Outside, a life-size bronze of the Indian from the Plains keeps a watchful eye on three retired Budweiser Clydesdales.

“Delivering on the American Dream Since 1982” is the slogan of Hendricks’ Beloit, Wisconsin–based roofing distributor, ABC Supply, and “American Pride” is one of the company’s seven core values. A video set to country singer Lee Greenwood’s “God Bless the USA” is shown to all company managers; Greenwood often sings it live at company events.

Hendricks believes in the American Dream because she has lived it. A teen mom who once worked as a waitress to pay her bills, she cofounded ABC Supply with her husband, Ken, in 1982 and built it into the nation’s largest wholesale distributor of roofing, siding and windows. After Ken died in 2007, Hendricks continued the business’s rapid expansion, buying rivals and more than doubling its store count to 900. Revenue hit a record $ 15 billion in 2021. “We’ll do close to $ 18 billion this year in sales,” Hendricks says. “It’s not a little company anymore. It’s five times what it was when Ken was alive.”

Hendricks, who owns 100 % of ABC in addition to a real estate development firm and a holding company with stakes in 18 businesses, is now worth $ 12.2 billion. That’s triple her net worth from just five years ago and more than any other female entrepreneur in U.S. history. By way of comparison, America’s second-richest selfmade businesswoman, Judy Faulkner, who pioneered electronic medical records (and who also lives in Wisconsin), is worth “only” $ 6.7 billion.

“The things she’s done, I’m not sure Ken could have done,” says Rob Gerbitz, the CEO of Hendricks Commercial Properties, her real estate firm, which recently paid $ 42 million for a hotel in Santa Barbara, California, and built a $ 40 million minor league baseball stadium in Beloit.

At 75, Hendricks is leaning into her success. She wants to influence everything from national politics and job creation to cancer research and public school reform. “Everyone knows I am a conservative,” says Hendricks, who has donated more than $ 40 million since 1992 to Republican candidates. That includes over $ 5 million in gifts to former Wisconsin governor Scott Walker and $ 50,000 to Scott Pruitt, Trump’s infamous EPA administrator, so he could pay his legal bills from a bevy of ethics scandals. Hendricks thinks one of the biggest problems facing businesses today is that not enough people appreciate their jobs. “It used to be that a job was a gift. You were proud,” she muses.

She takes that sentiment to heart. “I am so frigging old and still going to work because I still can think. I feel like I add purpose,” says Hendricks, who wakes up at 5 a.m. each weekday and is out the door by 7.

That work ethic was born on her family’s dairy farm in Osseo, Wisconsin, a rural town just southeast of Eau Claire with a population of barely 1,800. The fourth of nine girls, Hendricks wasn’t allowed to milk cows or ride a tractor (“men’s work,” according to her father), but she had plenty of chores, including taking care of her younger sisters. By age 10, Hendricks knew she wanted more than an agricultural life. “I don’t want to be a farmer and I don’t want to marry a farmer,” she remembers thinking. What she wanted was to wear a blue suit and work in the city – Minneapolis, the closest metropolis to her home.

Those plans were derailed when, in 1964, she got pregnant at 17 and was forced to drop out of school. She married the father and moved nearly 200 miles away to Janesville, Wisconsin; the couple divorced three years later. The newly single mom got a job as a bunny at the local Playboy Club. “You gotta do what you gotta do,” Hendricks says of that time.

Soon she was peddling real estate all over southern Wisconsin. She also started selling custom homes. That’s how, at age 22, she met a roofing contractor named Ken Hendricks. They married in 1976. The newlyweds bought up 200 old homes in three years, fixed them up and began renting them out to college students. “I cleaned a lot of toilets,” Hendricks recalls.

In 1982 they pledged everything they owned and took out a $ 900,000 bank loan to buy three struggling building supply stores. Their idea was to buy directly from manufacturers and then sell to contractors and project builders like Ken. The secret sauce was providing an unheard-of level of customer service in a notoriously unfriendly industry. Within five years, ABC had 50 stores and approximately $ 140 million in sales.

The company hit $ 1 billion in sales in 1998; the same year the Hendrickses recruited David Luck, a Bridgestone executive from Chicago, to become ABC’s president. With Luck at the helm, the couple looked to add new projects. “She and my dad had a passion for fixing failing companies, so they bought many out of bankruptcy and foreclosure,” says Konya Hendricks-Schuh, one of Diane’s seven children (including four stepchildren). Then the roof came crashing down, literally: On December 21, 2007, Ken returned home from a business dinner and went to check on a new roof above the garage. He fell through and died in surgery later that night.

Many people assumed Hendricks would get out of the business. A rival offered to buy the company. “They just thought, me being a woman, that I would sell,” Hendricks says. Instead, she asked Luck to become CEO and named herself chairwoman. It was a tough time, and not just because she had lost her husband of 40 years: Sales declined 7% between 2006 and 2009 as the real estate market collapsed. ABC closed stores for the first time.

Amid the turmoil, though, Hendricks smelled opportunity. Taking advantage of fire-sale prices, she orchestrated ABC’s biggest acquisition, buying $ 1.6 billion (sales) rival Bradco in 2010. Six years later, she paid $ 674 million for Chicago-based building mate­rials distributor L&W Supply. To fund the first deal, she gave up 40 % of her ABC stake to a backer on the condition that she could buy it back within five years. She did so in less than four. “I still get shivers right now,” Hendricks says, “because I felt that I had risked the company that I wanted my children to run. It’s not a company that’s ever going to be for sale.”

In the years since, Hendricks has made sure that her legacy extends far beyond a roofing business. On a recent humid August afternoon, Hendricks stands in front of a spectacular 20-by-30-foot sculpture of an American flag at the entrance to one of her pet projects: Beloit’s new Ironworks Campus. Since Ken’s death she has spent $ 85 million redeveloping the space, formerly an iron factory (the flag is made of 230 reclaimed machine patterns), into a gleaming complex that houses the local YMCA, Beloit’s Chamber of Commerce and 46 small businesses, employing 1,800.

Hendricks has plenty on her plate. A two-time cancer survivor – she had uterine cancer when she was 33 and breast cancer at 69 – she’s chairman of Northstar Medical Radioisotopes, which uses nuclear medicine and radio isotopes to detect and treat certain forms of cancer and heart disease. She’s already put $ 550 million into the company, which has just $ 10 million in sales, but she’s not giving up. Meanwhile, after seeing fewer than 20 % of Beloit teens achieve a “proficient” score on Wisconsin state reading tests, she helped fund a charter school in the city. The Lincoln Academy opened last year. She’s also expanding her chain of boutique hotels, moving out from Beloit to Indiana, Idaho and California.

The only real obstacle is time. “That’s the most frustrating part of getting old,” Hendricks says. “Golly, there’s still so much, so much to do!”

Text: Maggie McGrath
Fotos: Gabriela Hasbun / Forbes US