The Caisson Platoon is part of the 3rd U.S. Infantry Regiment, the nation's oldest active infantry regiment and the Army's "premiere ceremonial unit."
And now, this "old guard" is taking on a new role by helping to heal America's wounded veterans with the help of the horses.
Injured soldiers are transported from Walter Reed Army Medical Center each Thursday morning to the platoon's base in Fort Myer, Va., for weekly horse riding sessions.
Some soldiers are just learning to walk again; others are on prosthetics.
For them, the riding has proven to be therapeutic and shown dramatic results , according to the program's directors.
"The horses have done magic for them," Mary Jo Beckman, co-founder of Caisson Platoon Equine Assisted Programs, told ABC News' Bob Woodruff. "They tell me they look forward to Thursday morning... this is what makes life bearable for them," Beckman said.
Although the methods seem fairly simple -- proper riding posture and deep breaths while horse riding, the results can be felt as soon as the soldiers dismount and touch the ground.
"It...retrains those upper leg muscles to move the way you want them to move when you are walking -- either with your natural leg or with a prosthetic," explained Larry Pence, the other co-founder of Caisson Platoon Equine Assisted Programs."
One striking difference from traditional horse riding is that the wounded soldiers use pads, not saddles, to get a better feel of the horses' movement.
"When a horse moves at the walk, their hip movement is the same as yours and mine," explained Pence. "We want them to get in synch with the horse," Pence added.
In addition to helping soldiers walk easier, the weekly sessions also help alleviate the pain associated with prosthetics.
"It's great for your core," said Army Staff Sgt. Mike Cain, who lost a leg to a roadside bomb in Iraq. "You have to keep yourself stable and balanced enough to stay on the horse. You have to use yourself to stay up," Cain added.
But the therapy is much more than just physically beneficial – it has impacted the soldiers emotionally.
Retired Army Spc. Vincent Short suffered a traumatic brain injury in Iraq and has post traumatic stress disorder.
Short says his depression comes in waves, but the riding helps him tremendously, he told ABC News.
"This helps keep it at bay," Short said. "This is an outlet."
The riding has done more for Short than make his injuries bearable. It has strengthened his faith in himself.
"After riding several times, there are things I get to learn about myself...that just increases my confidence even more," Short said. "This right here is a great big confidence builder," Short said with a smile, as he patted his horse.
Short's testimony and his wide smile are just a couple of the rewards that motivate Beckman to continue her work helping Short and other wounded soldiers like him.
"This is why I do this," Beckman told Woodruff with a smile.
Remarkably, it is not just the soldiers who benefit. All around, each person involved in the program is rewarded.