Danny Lanigan, a Marine who had seen better days, was standing there, staring at the wall.

It was like he was looking at that wall in Washington, the one inscribed with the names of his buddies who didn’t make it back from Vietnam.

But it was a bare wall of the clinic on the second floor of the New England Center and Home for Veterans downtown.

Lanigan turned to Sharon Morrison, the nurse who runs the Boston Health Care for the Homeless clinic at the vet center.

“If I bring in a picture,’’ he said on that day four years ago, “will you put it up on the wall?’’

Morrison smiled. “You bet I would, Danny.’’

Morrison began working at the clinic in 2008, and it bothered her that the only photos on the clinic walls were, inexplicably, pictures of clowns. By 2013, she had been promoted to clinic manager and was in a position to do something about it.

She put up some photographs she took of the changing of the guard at the Tomb of the Unknowns at Arlington National Cemetery. Her patients took notice, and then Danny Lanigan started a process that continues to this day, of patients and those who work at the center bringing in photos of soldiers, sailors, airmen, Marines, and Coast Guardsmen from every conflict going back to World War II.

One of the photos is of Morrison’s father, Ralph, who joined the Army when he was 17 and saw combat. She sat with him when he was dying, and he confided that he was terrified when he got to Korea.

“Right after he died, this job opened up,’’ she said. “It was as if it was meant to be.’’

Adam Shenker, a benefits coordinator at the vets center and former Marine, crops and mounts the photos with precision. There are almost 150 photos on the clinic’s walls. There’s room for more.

The photos also include Morrison’s father-in-law and Shenker’s grandfather, who served in the Army in World War II. Trish McWilliams, a nurse, donated the 1943 telegram informing her family that her uncle had been killed in action in Italy.

There’s a photo of Patrick McCarthy, a Marine who used to work at the clinic’s front desk, talking to a boy in Afghanistan. There’s the female soldier who wrote the Army handbook on Ebola, a pair of smiling Tuskegee Airmen, a soldier brushing his teeth in open country in Afghanistan. The photos are of men and women, every color imaginable.

“The photos speak to veterans in a language they understand,’’ Morrison said. She was sitting there, remembering it all started with Danny Lanigan.

Lanigan had a thick beard and bushy hair that made him look like Forrest Gump when he finally decided to stop running. Exposure to chemicals in the service had ruined his health, and the war had taken other things, too.

But on that day four years ago, he handed Sharon Morrison a small photograph of himself in his dress uniform. He looked impossibly young, impossibly handsome. It took Sharon’s breath away.

She had the photo blown up and mounted.

“Danny was very proud,’’ she said.

Danny’s health declined rapidly after that. He was receiving hospice care at a nursing home in Mission Hill when Sharon got a phone call from someone with the US Immigration and Naturalization Service.

“Do you know where we can find Daniel Lanigan?’’ the man asked.

Danny Lanigan was born in Canada but fought for America. It took years and years to find his paperwork and finally, on his death bed,everything was in order.

Sharon Morrison, Danny’s sister and brother, and a few of his caregivers crowded into his hospice room as he was sworn in as an American citizen. He died two days later.

Danny Lanigan will always be on the wall of the veterans clinic downtown, speaking wordlessly to those who served, on Veterans Day and every other day, in a language all their own.

Kevin Cullen is a Globe columnist. He can be reached at cullen@globe.com