It is only a scrap of 86-year-old silent newsreel footage: an elderly black man named William Smallwood stands in threadbare clothes against a brick wall in Boston, performing the manual of arms with a wooden crutch. “Still ready if he’s needed,” declares a title card, presumably reflecting the old man’s sentiments. The clip is just one minute long. Smallwood provides no details of his life. Yet this bit of film is one of the rarest in existence. Not only does it capture one of the few moving images of an African-American Civil War veteran, but it may be the only one ever made of a soldier who fought with the famed 54th Massachusetts Regiment, made famous by the 1988 film Glory. (The clip inaccurately declares Smallwood to have been 109 years old at the time, proclaiming him the “oldest Civil War veteran”; he was actually about 85.)

Smallwood is just one of many Civil War veterans whose images may be seen and voices heard on reels of old film and audio recordings preserved in the collections of the Library of Congress. All are available to the public on request, although most are embedded in contemporary newsreels – for instance, a 1949 encampment of Confederate veterans in Arkansas is sandwiched disorientingly between a clip of President Harry Truman watching a staged airdrop of the 82nd Airborne Division and another clip of Don Newcombe hurling pitches to Joe DiMaggio in that year’s World Series.

To most of us, perhaps, the men who fought the Civil War may seem like the inhabitants of a sort of cinematic prehistory, quaintly memorialized in Currier & Ives prints, old newspaper engravings and the photographs of Mathew Brady. But here they are, like living ghosts in the flesh, the survivors of Bull Run and Antietam, Shiloh and Chickamauga, who saw Abraham Lincoln, Ulysses S. Grant and Robert E. Lee with their own eyes, and cheered their comrades into battle with these very voices that we now hear.

Thousands of Civil War veterans lived far into the 20th century. In 1913, 54,000 Union and Confederate veterans gathered at Gettysburg for the battle’s 50th anniversary, and an astonishing 2,000 were still alive to show up for the battle’s 75th anniversary in 1938. (Both events are represented in the library’s film and audio collections.) The last verified Union veteran died only in 1956, and the last Confederate in 1951. From the early 1900s through the 1940s, they were filmed, recorded and interviewed at reunions, parades and other patriotic events where, as the century advanced, they came increasingly to seem like ambulatory trophies from some distant age of heroes.

Most of the 20th century shows bent, bewhiskered and ribbon-festooned vets mingling with old comrades, visiting monuments, swapping memories and – a favorite trope of the era – shaking hands with their former enemies. By the late 1930s, faced with the looming threat of totalitarianism in Europe and Japan, Americans were more interested in national unity than they were in reliving old divisions. Typically, in a sound-only radio address at Gettysburg covered by NBC News in 1938, Overton Minette, commander-in-chief of the Grand Army of the Republic (the leading Union veterans’ organization) declares, to the sound of ceremonial cannon fire, “Let [us] be an example to the nations of the earth. . . that the deepest hate can be resolved into love and tolerance.” Following him, the Rev. John M. Claypool, the commander-in-chief of the United Confederate Veterans, drawls, “I have to forgive my brother here for anything that may have occurred between us. We can’t hold anything against each other.”

In this exclusive clip from the 1930s, Confederate veterans step up to the mic and let out their version of the fearsome rallying cry

Many clips are less solemn. In one newsreel, ancient but still frisky vets dance hoedown-style with a bevy of young women at a Confederate reunion in Biloxi, Mississippi. In another, also dating from the 1930s, old Confederates decked out in gray uniforms step up to a microphone and, one after another – their eyes flaring for a moment with the ferocity of their youth – let loose with the howling yelp that was once known as the fearsome “Rebel yell.” One of them, paunchy and stooped with the years, shrills, a bit unnervingly even now, “Go for ’em boys! Give ’em hell.”

First-person interviews are frustratingly few, and brief. Newsreel and radio reporters were clearly more interested in keeping things moving than they were in eliciting detailed recollections of the vets’ battlefield experiences. The often truncated fragments that survive can be tantalizing. Interviewed in 1938, one of the last survivors of Pickett’s charge, O.R. Gilette of Louisiana, declares, “We got about ten feet up the slope [of Cemetery Ridge], then we had to turn, then we run, run, run like hell.” A veteran of George Custer’s cavalry division who was present at Appomattox in the last moments before Lee’s surrender, interviewed by the same NBC reporter says, “We were about to charge, we had our sabers drawn, when a flag of truce appeared. . . ” when the reporter inexplicably cuts him off in order to move on to another subject.

Parades figure prominently in many of the film clips. One of the most remarkable shows a contingent of veterans marching briskly along a New York City street in 1905. In itself, it is not a particularly dramatic scene. But what it represents is extraordinary. The parade is actually the funeral procession for the last veteran of the War of 1812, Hiram Cronk, who had just died at age 105. A motor car brings up the rear carrying, it appears, several more infirm Civil War veterans. It is as if the 18th century were touching the fingertips of the 20th before our very eyes.

Sadly, in the eyes of the press, not all Civil War veterans were equal. No black volunteers served with the Confederacy, while African Americans contributed some 160,000 volunteers to the Union war effort. Yet they are almost never even acknowledged, much less seen or heard in the library’s films and recordings. Ironically, however, the most surprising film of African American “veterans,” a few minutes of silent footage made at a Confederate reunion in 1930, shows a dozen elderly black men wearing fragments of gray uniforms, flourishing miniature battle flags and wearing lapel buttons representing Robert E. Lee. Enslaved body servants, or perhaps laborers who had been pressed into service by Confederate armies, they were presumably served up to newsmen as “proof” that slaves were so loyal and happy in their servitude that they fought to retain it.

After Reconstruction, the role of African-American soldiers was largely airbrushed out of the war’s narrative in the name of national reconciliation. William Smallwood’s brief martial appearance against that brick wall in Boston thus stands as a powerful if all too fleeting reminder of both the sacrifice of the black volunteers who fought for the Union, and of the nation’s promises to them, so many of which would remain unfulfilled generations after the Civil War had ended.

Fergus M. Bordewich is the author of Bound for Canaan: The Underground Railroad and the War for America’s Soul, and Washington: The Making of the American Capital, among other works.