When 17-year-old Thea Leopoulos was killed in a car accident in Arkansas on Memorial Day of 2001, her father’s friend, Bill Clinton, left a round of golf at St. Andrews, Scotland, to fly to Little Rock to be with Thea’s father, Paul. Paul Leopoulos and Clinton had met in the third grade in Hot Springs, Arkansas, and had been friends ever since. The former president delivered Thea’s eulogy. Hillary Clinton, then a senator from New York, flew to Little Rock and stayed for three days.

In Thea’s memory, the Leopoulos family began a foundation to support the arts in schools. The largest single donor since it launched has been the Clinton Family Foundation, the little-known private family foundation of Bill, Hillary, and Chelsea Clinton, which has sent more than $1 million to the Thea Foundation to fund college scholarships, art supplies, and art in schools.

“We would not be at the level we are today, not even close to it, if it weren’t for his donations and for his believing in us,” Leopoulos said of Bill Clinton’s support over the years. “I don’t ever count on it. There are so many other people he could support, but there it comes every year.”

It was easy to miss, but after they left the White House, Bill and Hillary Clinton launched not one but two charities. The first was the Harlem-based William J. Clinton Foundation to impact issues of global significance.

The other was the smaller Clinton Family Foundation, the place where Bill and Hillary Clinton would direct their own private charitable contributions. While the larger Clinton Foundation grew to become an ambitious, often controversial, multibillion-dollar operation, the family foundation has remained a below-the-radar mechanism for the Clintons and their daughter, Chelsea, to donate to charities they personally support.

Unlike the Donald J. Trump Foundation, to which according to The Washington Post Donald Trump has donated less than $10,000 of his own money since 2008, the Clintons have given $22.5 million to the Clinton Family Foundation since 2001, according to 15 years of the foundation’s IRS 990 forms reviewed by The Daily Beast. Bill, Hillary, and Chelsea Clinton have been the only officers, have taken no salaries, have accepted no outside donations, and have no staff working for it.

As with everything else in the presidential race, the amount and motivation for the candidates’ past charitable giving have become embroiled in the politics of the fight for the White House, including in each campaign’s response to this article.

“The Clintons have consistently donated about 10 percent of their income each year to charity because they believe strongly in giving back to their community and helping people in need,” said Josh Schwerin, a Clinton campaign spokesman, adding, “While others lie about their charitable giving in order to boost their own image, the Clintons do this simply because it’s the right thing to do.”

A Trump Foundation spokesman told The Daily Beast that Trump has donated “tens of millions of dollars to charities both through his Foundation and otherwise. In addition, friends of Mr. Trump have generously donated to his Foundation.” Like the Clintons, the spokesman said Trump takes no compensation for his role in his foundation and that he makes “regular personal contributions” to charities outside the Trump foundation. “All in all, the Foundation supports many worthy causes, and the Foundation distributes its funds to get the money into the hands of those in need as soon as possible.”

But outside the Trump campaign’s statements, there is no way to know anything more about the “tens of millions of dollars” Trump says he’s donated throughout the years. The campaign and Trump himself have declined to elaborate on his giving or to release tax returns detailing his philanthropy. In contrast, Hillary and Bill Clinton’s tax returns for the last nine years are posted on her campaign’s website, while the IRS disclosure forms detailing the Clinton Family Foundation’s activities are easily accessible and provide a detailed history of the family’s philanthropy over 15 years.

About 20 percent of the family foundation’s donations, $5.39 million, has gone to the larger Clinton Foundation. The rest has been spread out in increments large and small to dozens of nonprofits across the country. Like the Thea Foundation, many have ties that go back to the Clintons’ earliest Arkansas days.

Little Rock’s Immanuel Baptist Church, which Bill Clinton joined as governor, has received $525,000 since 2002. The foundation also has sent a donation every year to Rose Hill Cemetery in Hope, where Bill Clinton’s parents are buried, as well as the Clinton Birthplace, a fund to maintain Bill Clinton’s childhood home. They’ve given multiple contributions to the Arkansas Single Parent Scholarship Fund, which Hillary Clinton began as Arkansas’s first lady, and donated $100,000 to the Arkansas Children’s Hospital, where Hillary Clinton served on the board and launched the state’s first neonatal nursery.

The foundation has also spread more than $1 million across multiple colleges, universities, and high schools, including $200,000 to the University of Arkansas and annual five-figure contributions to Georgetown University, Wellesley College, and Yale Law School. It has also given multiple donations to Sidwell Friends, the private school in Washington, D.C., that Chelsea Clinton attended, and in 2009, $4,500 to the Redondo Union High School Lacrosse Team. If that seems a little random, it’s not. Roger Clinton’s son—Bill and Hillary’s nephew—was on the team at the time.

A common theme among the organizations the foundation supports are names with unique ties to the Clintons. The foundation has given $100,000 to the Children’s Defense Fund, where Hillary Clinton once worked, and another $100,000 to the Marian Wright Edelman Fund, which honors the founder of CDF. Vital Voices, the global women’s nonprofit cofounded by longtime Hillary Clinton aide Melanne Verveer, has received more than $200,000 for its work, while nonprofits with ties to longtime Clinton associates like Doug Band, Cheryl Mills, and Rolando Gonzalez-Bunster, an energy executive and Clinton Foundation board member, have gotten smaller gifts.

Because the Clintons are the Clintons, celebrities’ foundations have received Clinton cash, too, including the personal foundations of Oprah Winfrey, Tiger Woods, Andre Agassi, Ralph Lauren, and celebrity chef Mario Batali. When Bill Clinton headlined the tsunami relief effort with former president George H.W. Bush, the foundation gave $100,000 to the cause. When he did the same for Hurricane Katrina recovery, the foundation donated $75,000.

In the “good neighbor” category, the foundation also gives annually to the Clintons’ local public radio stations and kicks in a few thousand dollars every year to the Chappaqua Volunteer Fire Department and Volunteer Ambulance Service.

It all seems like a good news story waiting to be told. But like so many things in Clinton-world, the family foundation has been oddly unpublicized and, initially at least, went partially undisclosed to the public.

The foundation has no website and has never issued a press release about a gift. Although Hillary Clinton served as the family foundation’s treasurer throughout her time as a U.S. senator, she failed to include the foundation or her role in it on her annual disclosure reports to the Senate for six years. Once it was reported by The Washington Post in 2007, Clinton’s Senate staff filed an amended disclosure report the following day.

As usual, some see the Clintons’ lack of information about the family foundation as a sign of their arrogance. Others see it as a sign of their humility.

“They don’t ever go out and brag about what they’re doing. They’re very private people and very good friends,” said Paul Leopoulos. “This is the family foundation, not the Clinton Foundation. They’re not the same thing.”