In the fall of 1942, Michael Decker anchored the Warren Easton Fighting Eagles state champion football team as a center on offense and a linebacker on defense. But before he completed his senior year, Decker laid down his shoulder pads to take up a rifle as a Marine, and he headed off to the Pacific to fight in World War II.

“It was just what everybody was doing,” he said.

On Wednesday, representatives of Warren Easton were at the Trace Senior Living Community in Covington, where Decker now lives, to formally award him the high school diploma he passed up getting seven decades ago.

Perhaps more importantly for Decker, who has remained an ardent Fighting Eagles football fan, they gave the 89-year-old a letter jacket embroidered with an “E” for Easton and Decker’s name and year.

“Can you help me put it on?” he asked when he saw the jacket.

Wednesday’s presentation, which was a surprise to Decker, was the culmination of about two months of work begun by Richard Totorico, the executive director at the Trace.

Decker, Totorico explained, mentioned a couple of months ago that he had never received his diploma from Warren Easton. He asked if Totorico could help him get it, along with a letter jacket for the years he played football.

Totorico reached out to school officials. At first, records of Decker’s attendance couldn’t be found, and the school resolved to present him with an honorary diploma, according to David Garland, president of the school’s board.

But then, someone found Decker in an old yearbook, and further research showed that he had earned enough credits to graduate from the school. The school worked with state officials and was able to give Decker a real diploma, Garland said.

But that wasn’t all. School officials knew Decker was a big fan of the football team because he occasionally sends them notes of encouragement. So they contacted the vendor that makes the Fighting Eagles letter jackets to see if they could reproduce one that would look close to what Decker would have received back in 1942.

When they had it all together, they enlisted the help of Decker’s children, Annie Schneider and Michael Decker Jr. While the senior Decker was upstairs, staff at the home set up a podium, a chair and a gallery. Speakers were readied to play both the Warren Easton fight song and the Marine Corps hymn. Staff, residents and media gathered to watch.

Annie went upstairs to collect her father, ostensibly for a doctor’s appointment. Photographers clustered around the elevator, where Decker emerged a few moments later, wearing a World War II veteran’s cap and a surprised look.

Totorico approached him and said, “Mr. Decker, you’re getting your diploma today.”

Decker’s reply was drowned out by noise, but his daughter quoted him as saying, “But I’ve got to go to the doctor.” Then, when he realized that the doctor’s appointment was a ruse, he asked Totorico, “Did you get my jacket, too?”

After Garland made a few remarks, Warren Easton head football coach Tony Hull presented Decker with his purple-and-gold jacket and helped him don it.

Later, surrounded by family — his grandson, Michael III, and great-grandson, Colby Decker St. Hilaire, were also there — and well-wishers, Decker wore the jacket with a broad smile.

Decker served in heavy artillery in the Marines, helping fire 155 mm cannons at Guadalcanal and Okinawa, among other places.

On Wednesday, he told stories about some of the places he had been, and of people he knew in high school who died in the war. But he fondly remembered his days as a Fighting Eagle.

Watching his father proudly wear his new jacket, Michael Decker Jr., who wore his own Chalmette High School letter jacket in support, said he knew the gesture meant a lot to his father.

“We’re all big football fans, and having that jacket is a big deal,” he said.

The elder Decker, who strutted around the Trace lobby in his new jacket before eating some celebratory cake, echoed those sentiments.

“This is the greatest thing that’s happened to me since I have been here,” he said.

Follow Faimon A. Roberts III on Twitter, @faimon.