On Wednesday, Keeler pinned an insignia on his grandson's uniform, officially making him a lieutenant colonel.
Marquart made special arrangements for the ceremony to take place in Wichita because he wanted his grandfather, who couldn't travel due to health complications, to take part. Marquart has never met his father.
"My grandfather is my male role model in my life, and he's the only one I've had," Marquart said.
Marquart is stationed at Tripler Army Medical Center in Honolulu, where he serves in an administrative role. He is a nurse practitioner. He flew his commanding officer, Col. Judith Dickert, and her husband Navy Cmdr. Tom Bellit to Wichita for the ceremony.
"I don't think many people would spend thousands of dollars to fly someone in just so their grandpa could be involved," said Monica Keeler, Marvin Keeler's wife.
Marquart said there was never a question of how he wanted the ceremony to go.
"Is it an investment? Yes, but it's a memory," Marquart said.
Marvin Keeler said he was "kind of humble" about what Marquart did for him. He said he is proud of where Marquart has gone in life.
"He just took what was available and pursued," he said.
Marquart was born to a single mother and moved to Wichita when he was in fourth grade.
"He didn't come from a background that was -- I mean he lived in a poor neighborhood, he didn't have a lot of things, although he certainly had food and a roof over his head all the time," Monica Keeler said. "I mean even in high school ... he's always kind of pushed himself just pushed himself. And this is what has brought him to where he is today because he wouldn't just quit after one thing. If he got done with that he pushed on to something else."
Marquart joined the Army after he graduated from Derby High School when he was 17 in the early 1990s. He was deployed to Iraq in 2003 and Afghanistan in 2013.
"Originally it was because I thought it would give me a job outside of the military," Marquart said.
He has stayed in the Army for more than 25 years because the Army gave him the opportunity to go back to school and earn degrees.
He got to help people on their worst days, and now as an administrator at Tripler, he helps train the next wave of Army nurses.
"If I do clinical care, then that means someone else has to do admin stuff and no one wants to get to that point in their career," he said.
This will likely be Marquart's last promotion in the military.
"I'll probably serve another three to five years and then I'll retire ... ," he said.
The ceremony lasted less than five minutes as Col. Dickert's husband read Marquart's orders and Marvin Keeler exchanged his rank and uniform. Two of Marquart's children, his wife, his grandparents, his mother and her husband came to the ceremony in 20-degree weather.
There ceremony was held in front of the Korean War Memorial in Veterans Memorial Park.
"I wanted to find a landmark that honors both previous service and my grandfather," Marquart said. "As a Korean War vet, a Marine Corps Korean War vet, he deserves as much recognition for his service as I do for any service that I do."
--This article is written by Emily Wellborn from The Wichita Eagle and was legally licensed via the Tribune Content Agency through the NewsCred publisher network. Please direct all licensing questions to firstname.lastname@example.org.