The inside story of how all five living former U.S. presidents came together in one video to raise donations for Hurricanes Harvey and Irma relief

In these divided political times, you might think it’d be difficult to unite five former presidents of different parties for a common cause. But that’s exactly what the father and daughter team of Roy and Courtney Spence did — and in just 48 hours — when they helped organize and film bipartisan PSAs for Hurricanes Harvey and Irma relief featuring former commanders in chief Jimmy Carter, George H.W. Bush, Bill Clinton, George W. Bush and Barack Obama.

Roy, a co-founder of the Austin-based advertising firm GSD&M, and his daughter Courtney, the founder and CEO of the creative film agency CSpence Group, had previously co-produced public service announcements with Clinton and the elder George Bush for the Bush-Clinton Katrina Fund, and with Clinton and the younger George Bush for the Clinton Bush Haiti Fund.

But on the Saturday of Labor Day weekend — after Harvey had ripped through Texas, killing dozens and leaving thousands injured and more than 1 million people displaced — Roy got a call from George H.W. Bush’s spokesman, Jim McGrath, saying all the living former presidents wanted to come together for “something historic.”

“He said the presidents wanted to help out 41 and 43 with their funding for the victims of Harvey,” Roy tells PEOPLE of George H.W. Bush, the 41st president, who lives part of the year in Houston, and his son George W. Bush, the 43rd president, who lives in Dallas.

Roy immediately responded with a “yes” — and was then informed of two “little, slight catches.”

Firstly, the ad would have to be ready to air in less than a week as the NFL had donated prime time that Thursday night to debut the PSA during the league’s opening game. No problem, Roy said.

The second catch was that none of the presidents would be in the same location.

“I get off the phone, I’m crying, so I called my daughter,” Roy says. “I said, ‘Hey Court, we’ve got a labor of love here. And I told her the situation and she said, ‘Dad, I am all in.’ ”

It was a common response throughout the whirlwind process of organizing five production crews in five different cities in the span of 36 hours, says Courtney.

“It was an all-volunteer effort,” she says. “I’ve never seen people mobilize, I’ve never seen people say yes, I’ve never seen people donate their time like this before. People stopped what they were doing and got on planes … It was amazing.”

Three days later, everything was in order for filming to begin in five different cities across the country. But in the early morning hours of Sept. 5, as Roy was watching coverage of the hurricane on TV, he said, “All of the sudden it hits everyone that it’s not just a Harvey problem; Irma is on the way through the Caribbean headed to Florida.”

Roy called McGrath, and they decided to come up with a script for a last-minute second video featuring the presidents and raising funds for both Hurricane Harvey and Hurricane Irma aid. All five presidents quickly approved the script to shoot that same day.

“On Tuesday, we started filming at 9 a.m. in Maine with Papa Bush and ended with Bill Clinton at 7:30 at night,” Courtney says.

While on set with Clinton in San Diego, Courtney says she had a conversation with the former president about the special relationship between Louisiana and Texas, which came to New Orleans’ aid after Hurricane Katrina hit in 2005. “The president’s passion and compassion for this was palpable,” she says.

“I think at a time when our nation is really hurting from Harvey and Irma, to see these five men come together as swiftly as they did and to raise the funds that they have — not only was it needed, it was just really inspiring,” she adds.

The first PSA, titled “Our Friends in Texas,” quickly made an impression after it aired on Sept. 7, officially launching the presidents’ “One America Appeal” initiative to raise funds for organizations assisting victims of Hurricane Harvey and Hurricane Irma. (The second PSA addressing both hurricanes aired a few days later.)

Both Courtney and Roy say they’ve heard stories of people who felt inspired by the ads to put aside their political differences and come together to help their fellow Americans after the disasters. A friend who was running an evacuee shelter in Beaumont, Texas, told Courtney she overheard someone there say, “If those guys can work together, then we can work together.”

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But many viewers couldn’t help but notice President Donald Trump‘s absence from the PSA, especially given the past friction between Trump and his predecessors.

Trump knew about the effort in advance, Roy said. But Trump was not invited to participate, confirms another source knowledgeable of the project who requested anonymity discussing what could be perceived as a snub. A third source familiar with the project told CNN that although the White House was notified ahead of the PSA, the effort was always intended to include only the former presidents.

The source told CNN that excluding Trump “wasn’t intended as a slight and wasn’t because of the animosity that’s lingered between President Donald Trump and his predecessors.”

Trump, who personally donated $1 million in recovery efforts after Harvey, offered his backing for the presidents’ appeal after the ad aired on Sept. 7, tweeting: “We will confront ANY challenge, no matter how strong the winds or high the water. I’m proud to stand with Presidents for #OneAmericaAppeal.”

Roy says the PSA was not intended to be political, but to unite Americans and “appeal to people’s best instincts.”

“Forget the politics of it all, I think that right now there’s a hunger in the soul of America that says, ‘We are better together,’ ” Roy says. “In the endgame, I actually believe that when you appeal to people’s best instincts it brings the best out of everyone.”

“I think when things are really tough, America is at her best — we don’t come apart, we come together,” he adds. “We got a higher calling here, and I think pretty much everybody answered the call.”

So far, One America Appeal has raised more than $4 million from 16,000 donors from all over America.

Donations may be made at One America Appeal’s website.