CHICAGO — Patrick Furlong’s 16th birthday wish was simple: to know how his dad lost his leg in the Vietnam War.

At 21, Jim Furlong had seen an enemy soldier toss a hand grenade. He jumped as high as he could, hand stretched out. It brushed his fingers, then dropped to his feet.

It took 30 years before Furlong recounted those minutes out loud for the first time, and he only did it for his son.

“I kept it all bottled in for a long time,” Furlong said. “I just didn’t think I wanted to talk about it.”

On Sunday, National Purple Heart Day, Furlong told that story once more, as did seven other local Vietnam War veterans who have received the military award. Transcripts of their interviews are part of an ongoing Library of Congress project to document the personal accounts of veterans from World War I through the Iraq War.

Vietnam War veterans in particular said many of Sunday’s participants returned home without a homecoming. Instead, they felt pressure to swallow the horrors of warfare and get on with the reality of civilian life. The Veterans History Project, they say, is now immortalizing their experiences after decades of suffocation.

“It dawned on me that veterans don’t go out there and tell these stories,” Furlong said. “That’s a disservice to the people who didn’t come back. That’s a disservice to the people I’ll always remember being 20 years old. I’m their voice.”

Created by George Washington in 1782, the Purple Heart — awarded to soldiers wounded or killed in combat - is the United States’ oldest existing military honor and has been awarded an estimated 1.8 million times.

Military members slammed Republican presidential nominee Donald Trump last week after he said he “always wanted to get the Purple Heart,” and that receiving one as a gift from a veteran was “much easier” than serving in combat. The incident occurred just days after Trump engaged in a feud with the parents of a Muslim soldier who was killed by a car bomb in Iraq and awarded the Purple Heart. Khizr Khan, the soldier’s father, had criticized Trump at the Democratic National Convention.

Daniel Finn, 69, of Oak Lawn, Ill., received a Purple Heart for his service in Vietnam in 1967. He said unlike some other military decorations, the award has to be earned in combat.

“If you see a Purple Heart, they shed blood for their country,” he said.

On Sunday, Finn described how eight months into his tour of duty, his unit was ambushed and he lost his left foot in an explosion. He was 19. It wasn’t until his own son toured in Iraq in 2004 that he started talking about that day, even to his wife.

“You can’t explain adrenaline, you can’t explain the fear and the rush and your reaction,” Finn said. “It’s something you really don’t want anyone else to experience; there’s just some things you don’t share.”

John Domina, 65, of Tinley Park, Ill., said warfare smelled like diesel fuel, mold and hot dirt. It tasted like C-rations marked from 1944. It isolated soldiers who didn’t care to learn names they might have to soon forget.

Every morning, from the first weeks of duty to the last day, Domina said, was marked by a distinct and constant fear: Is today going to be the last?

He and Kenny LaForge, 64, of Antioch, Ill., served in the same unit in 1970 and were wounded in the same three-hour firefight. They still chat two to four times a week and go to Maggiano’s every April 18, the anniversary of their injuries: a cracked skull and perforated eardrums for Domina, a traumatic brain injury for LaForge, and plenty of shrapnel for both.

In a joint interview for the Library of Congress project Sunday, they both agreed they were greeted upon return with apathy and hostility, unlike the soldiers of international wars before them who were hailed as heroes.

“There was no welcome home; it just didn’t happen,” Domina said. “Even your family didn’t want to hear your story. Nobody cared. It was expected that you forget what you did and get a job. It’s amazing that 50 years later people are interested.”

Within weeks, the National Court Reporters Foundation, which coordinated Sunday’s event, will have submitted 4,000 completed transcripts for the Veterans History Project.

In an age where military life can feel abstract and faraway, it’s imperative to document the personal accounts of those who served on the front lines and in commissaries, offices and the Pentagon, said B.J. Shorak, the foundation’s deputy executive director.

“Put together, we have all these stories and perspectives of what it takes to run the military and conduct a wartime effort,” Shorak said.

Since its 2000 launch, the Library of Congress effort has only become more salient as upward of 1,000 aging veterans die every day, said Mike Nelson, a Vietnam-era veteran and CEO and executive director of the National Court Reporters Association.

“Maybe we can learn from their experiences and recognize what a devastating situation war is,” Nelson said, “and understand from their emotional perspective why there’s always a need to avoid it.”