As he prepared to participate in the historic first inauguration of Barack Obama, Benny White was himself portraying a key part of American history as a leader of the Civil War reenactors who re-created the 54th Massachusetts Volunteer Infantry Regiment — one of the nation’s first all-Black military units.

“I always just had an interest in the historical part of the story,” Mr. White told the Globe as he commanded the regiment in drills along Taunton Avenue in Mattapan on a cold January morning in 2009, before heading to Washington, D.C., to march in the inauguration parade. “It is the history of this country — an unspoken part of the history that a lot of us never know about.”

Mr. White, who was 75 when he died in his Mattapan home of a heart attack on July 4, spent countless volunteer hours ensuring that this chapter of history was honored and remembered.

“Benny was the heart and soul of motivating a lot of generations of young folks to keep these highest ideals in mind,” said David Hencke, a retired Army lieutenant colonel and executive officer of the 54th Volunteer Regiment. “It’s a great American story.”

Though he had served in reenactments as a first sergeant and then as a lieutenant, plans had been underway to promote Mr. White to captain, Hencke noted. That promotion became part of Mr. White’s memorial service.

“We buried him as a captain,” Hencke said.

After the 1989 film “Glory,” starring Denzel Washington and Morgan Freeman, popularized the accomplishments of the 54th Massachusetts Volunteer Infantry Regiment, Mr. White and George Coblyn cofounded a local group that became the reenactor unit.

“He dedicated his life to it,” said his brother Marco White of Hyde Park. “Everything in his life was the 54th.”