Houston billionaires Rich and Nancy Kinder told ABC13’s Melanie Lawson they plan to donate an astounding 95% of their multi-billion-dollar wealth to charities.

It comes as the Kinder Foundation announced an $18.5 million expansion project for Emancipation Park in the heart of Third Ward.

That historic park was founded by slaves in 1872.

While you may not know the Kinders, you’ve certainly seen the Kinder name on buildings and facilities around the city of Houston.

They are one of the wealthiest couples in the nation, worth $11.4 billion, according to Forbes.

The Kinders are also among the most generous, giving away hundreds of millions to Houston institutions and charities. Their plan is to give away almost all of their wealth, or more than $10 billion.

Rich Kinder helped build oil and gas pipeline giant Kinder Morgan, but he stepped down as CEO more than a decade ago for a what he calls a bigger cause.

“Well, I think we’d all like to leave the world a little better place than we found it,” Rich Kinder said. “And we just felt early on that the right thing to do was to try to give most or all of that away. So that’s what we plan to do during our lifetime and after our death.”

They found kindred spirits, as one of the first couples to sign a pledge established by billionaires Bill and Melinda Gates, and Warren Buffett.

“There were only, I think, 20 people when we joined,” Nancy Kinder said. “The first meeting was 20-something families or people, couples.”

The pledge they signed at the time was to give away at least 50% of their wealth – but the Kinders instead chose a much bigger number – a whopping 95% in donations through their Kinder Foundation.

While other big donors aimed for world-wide projects, the Kinders wanted to keep their efforts close to home, with very specific goals.

“So we decided early on, our core principles would be that we would invest most of our philanthropy in Houston and then that we would try to concentrate on really three areas that we thought really needed help,” Rich said, “that’s education and urban green space and then kind of a lump-it-all-in quality of life.”

One of their first major efforts was to build a park among the downtown skyscrapers.

It became Discovery Green and was completed for roughly $25 million. Nancy calls parks the great equalizer.

“Well, it’s a melting pot of people, dogs,” she told ABC13. “Whenever you’re in a park, there’s one of everybody. And people are friendly, you know, you talk to the dogs. It’s just, it is our happy place in all of these parks.”

The power couple has made huge investments in other city parks – $8.5 million for dozens of Spark parks in schools, $34 million to Buffalo Bayou Park, $12.5 million to Emancipation Park before this week’s expansion donation to $2 million to Harmon Park.

The most transformative green space gift is $82 million and counting to build Memorial Park’s massive land bridges.

They’ve also given $77 million to fund the Kinder Institute for Urban Research at Rice University and nearly $86 million for a new building for modern art at the Museum of Fine Arts Houston.

But their biggest investment – $150 million – is for a new hospital to battle childhood cancer, by joining two powerhouses, Texas Children’s and MD Anderson.

Rich outlines their decision, “when you couple MD Anderson with their tremendous Nobel Prize-winning research in cancer generally and Texas Children’s with their great background of knowing how to treat children, it’s just a tremendous combination.”

So far, they’ve given more than $900 million to southeast Texas causes and organizations.

Both Rich and Nancy grew up in modest conditions – he’s from Missouri, and she lived in Louisiana – before moving to Houston, and he gets emotional when he talks about giving back so much to the city they love.

“You have to be grateful for everything that this country has given us, you know. It’s not fashionable today to talk about this, but I think the ability to grow and become successful in this country is pretty unique,” he said, “You think, well, if it’s been good for us, why can’t we share some of this and be good for other people too.”

“I think some of the projects that we’ve done here, I’m really proud of them, and I think they’ll last forever,” Nancy said. “So if I want our grandchildren to be proud of us, and I think they are. And I want them to know that’s what we expect of them when they grow up. They have to give back, and it’s not all about us. They have to carry it forward.”

The Kinders say they’re far from done.

They’ve invested millions in the historic Third, Fourth and Fifth Wards, and now they’re planning a $27 million renovation of McGregor Park.