Long before the streaming services made the label “made for television movie” respectable, there were stand-outs in the stepsister genre that showed you didn’t need Hollywood backing to make a good movie. Spielberg’s breakout “Duel” is the best known example.

But PBS, keeping to its enlighten/educate mission, turned out quality films on important hot-button subjects via its series, “American Playhouse.” That’s where “The Killing Floor” found its home, an early work of resonant power from African American actor-filmmaker Bill Duke, who would go on to direct lots of TV and some solid genre films, “A Rage in Harlem” and “Hoodlum.”

“The Killing Floor,” newly restored for Film Movement, is a well-researched, swirling period piece about the real people who integrated Chicago’s stockyards and unions in events leading up to the city’s post-World War I race riots of 1919.

It’s a rough-hewn film, crudely incorporating newsreel footage of the day with grim, unblinking cattle slaughterhouse footage of today and leaning far too much on voice over narration to tell its story of one member of the African American diaspora who came to Chicago from Mississippi to find himself in the middle of a labor struggle and a racial one.

But it’s impressive in its detail and startling in its ambition, and thanks to capturing a legion of actors about to become famous — from Alfre Woodard and Dennis Farina to Ted Levine, Mary Alice, Stephen McKinley Henderson and John Mahoney — beautifully acted.

Damien Leake is Frank Custer, a sharecropper who leaves behind his wife (Woodard) and family to seek work in the Big City during the Great War. He and his traveling partner Thomas (Ernest Rayford) are startled on arrival to see that “colored folk had built their own city.”

That city-within-a-city in Southside Chicago included a support system, where the YMCA provided job counseling/placement through M. Cheeks (August Wilson favorite Stephen McKinley Henderson). That’s how the guys end up at the sea of cattle and meat processing known as The Stockyards, an eight-story killing machine where “they didn’t waste NOTHING” — tail to hides, steaks to brains.

Duke shows us about as much of this as PBS would allow in 1984.

Frank gets his start mopping blood off the floor, and trying to keep his head down as the Poles and Slavs who dominated the workforce bellyached that “there’s as many of them as there are of cattle.” “The Great Migration” was underway, and war or no war — white jobs were being threatened.

Frank finds himself befriending the Pole Bremer (Clarence Felder). That’s how he’s recruited for the meat packing union. And that’s how he finds himself going toe to toe with the “packers” (corporate, represented by Mahoney) and with older workers like the jaded Heavy (Moses Gunn).

Thomas? He takes one beating (for being “mouthy”) too many and decides the Army’s for him. As it turns out, he returns to town just in time for all the wage pressure/job shortage/racism stuff to come to a head.

As I mentioned earlier, there’s a clumsiness to the integration of different film stocks and the reliance on voice-over to tell us what we can figure out for ourselves. “Floor” looks too much like a “TV movie” of the day for its own good. It’s not a great film, but it’s a lot more than an interesting artifact.

But I was startled by the clarity of the story which Duke finesses from the over-eager and overly earnest Leslie Lee/Ron Milner script, which throws a whirlwind of characters, conflicts and events at us hoping that we’ll keep up.

Woodard’s trademark sexy-earthiness is obvious, even early on. Gunn was already an accomplished character actor, and Farina was — I think — still a cop when he took this role, years away from “Crime Story” and “Get Shorty.”

The leading men are quite good, if not dazzling in that pop-off-the-screen way that points towards stardom.

The presence of Henderson, of “Fences,” places the film within that broader depiction of African American working class struggles that were playwright August Wilson’s raison d’etre. This historical piece is Wilson-esque, if not polished and pungent enough to pass off as one of his own.

But considering the timing — making this in the middle of Ronald Reagan’s war on labor and on African America — “The Killing Floor” plays like a landmark far more important than its “history on a budget” look.

MPA Rating: unrated, some violence, animal slaughter, racial slurs

Cast: Damien Leake, Alfre Woodard, Ernest Rayford, Moses Gunn, Clarence Felder, Mary Alice, Dennis Farina, Ted Levine and John Mahoney

Credits: Directed by Bill Duke, script by Leslie Lee, Ron Milner, story by Elsa Rassbach. An American Playhouse film, a Film Movement release.

Running time: 1:58