Nearly 25 years after he starred alongside Tom Hanks in Forrest Gump, Gary Sinise is sharing how the film still impacts his life.

ET was with the 63-year-old actor as his charitable organization, the Gary Sinise Foundation, treated 1,000 children of fallen military members to a vacation at Walt Disney World in Orlando, Florida. And before the fun-seekers arrived, Sinise shared why his film experience makes the cause closer to his heart.

“The fact that Lieutenant Dan was a wounded Vietnam veteran -- he's kind of played a bigger role in my life because of the nature of what that character was,” Sinise noted while reflecting on filming Forrest Gump, in which he played Lieutenant Dan Taylor, the commanding officer of Hank's titular character. “He was a wounded, injured solider, and I remember going into the first hospital to visit an injured soldier after Sept. 11, and all he wanted to talk about was Lieutenant Dan and what happened to Lieutenant Dan. So, that character has obviously been very special to me.”

The Disney World trip was part of the Snowball Express program, which saw American Airlines provide 12 aircraft to fill with Gold Star families (who have all lost a family member in military service) so that they could fly to Orlando for “chaos, craziness and lots of joy” at the theme park.

“When they get off the plane a lot of people will be there to welcome them,” Sinise shared. “We have a lot of things planned at the park, but also this is our first time at Disney World, so we want them to go out and enjoy the park, and then we have central things happening throughout their four-day event where the whole group gets together. I'll be there on Tuesday to play a big concert with my band, The Lt. Dan Band, for the finale and that's how we usually end the event every year.”

Sinise noted that having the opportunity to meet and spend time with other youngsters who had been through similar experiences is a valuable experience for the children.

“When we bring all these kids together, they get to bond with each other,” he said. “It's very, very healing and they see that they're not alone going through this grief by themselves and other kids are going through the same thing. We just give them a lot of love and a lot of joy and make sure that they know that they're appreciated and that we don't forget what they're going through.”

Snowball Express was started in 2006 to help the children of fallen heroes. Sinese got involved in the initiative early on and now the program has been adopted by his own organization, the Gary Sinese Foundation.

The former CSI: New York  actor felt it was important to help the children of fallen soldiers since “we’re all the beneficiaries” of their parents’ service.

“We still have people deployed in harm’s way -- they're still getting hurt. We're still losing service members and they have children,” Sinise said. “Those children are going through a lot of difficult things when they lose a parent in military service. We're all the beneficiaries of what their parents do to protect our freedom and protect our country. So, I believe there's a way that we can show our support and help them through these difficult times and that's what we do at the Gary Sinise Foundation each and every day.”

The actor added that he has a special connection with Disney World, having taken his children there at Christmas time for years to narrate a candlelight processional.

“My kids grew up at Disney World at Christmas time, so it will be very special for me to take over 1,000 kids down there and celebrate the holiday season with them and see them have a good time,” he said. “Then I'll stay and narrate the processional once again -- that was kind of our holiday tradition for many years.”

As for Forrest Gump, which celebrates its 25th anniversary next year, Sinese still finds it hard to fathom what an iconic film the project turned out to be.

“None of us really knew what it was going to turn into or that it would be the big hit that it was, but we all really enjoyed working on it,” he said. “I had a great time working with Tom. I ended up doing two more movies with him after that, [but] that one is always going to be a special memory.”

See more on stars giving back below.

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