The first character we meet in Signature Theatre’s production of Dominique Morisseau’s “Confederates” is an elegant black woman in a brightly colored blazer who is managing a difficult situation with utter composure. For anyone who’s been following the news even casually over the past week, she immediately brings to mind the current nominee to the Supreme Court. 

But where Judge Ketanji Brown Jackson has lit up CSPAN with her smile — even while fielding disingenuous and occasionally idiotic questions — Ms. Morisseau’s Sandra, an accomplished and popular political science professor at an elite university, would be hard-pressed to even force a grin. While enmeshed in a harrowing divorce, the scholar shows up at her office one day to find an appalling image taped to her door: Her face has been photoshopped into a picture of a female slave enduring a racist, sexist indignity.

Another slave acts as Sandra’s fellow spirit in the latest offering from Ms. Morisseau, whose acclaimed works include the three-play series “The Detroit Project” (featuring this season’s Broadway offering “Skeleton Crew”) and “Pipeline.” Sara is a young woman who lives more than a century before Sandra but responds to her circumstances with a similar blend of courage, frustration, and aspiration. Where the slave yearns for literal, physical freedom, the professor is seeking the spiritual equivalent all these years later.

For Sara, who is instilled with both endearing innocence and a spry wit in Kristolyn Lloyd’s excellent performance, the quest leads to an arrangement with her owner’s adult daughter, a self-styled progressive who enlists the slave to spy on Confederate Army council members as they meet with her father. Sandra, played with grace and force by an immensely likable Michelle Wilson, must deal with the assumptions and accusations of students and colleagues — male and female, white and black — fed by stereotypes and self-interest. “Everyone seems to think there’s a bias toward something,” she muses.  

Shuttling between past and present, “Confederates” also juggles satire with more sober, even didactic commentary, sometimes at the expense of nuance. There are only two white characters — both played, hilariously, by Kenzie Ross — and each is an entitled, vapid woman. Missy Sue, the plantation master’s daughter — whose interest in Sara, as it turns out, extends beyond a passion for social justice — whimpers and preens as she cluelessly patronizes the grown woman who was forced to play with her as a girl.

Sandra’s student assistant, Candice, is an updated model of white privilege as it manifests itself in young women. Whining about unfaithful boyfriends and having to take 10-minute showers,  she’s a rather curious creation from a playwright whose concerns include gender-based clichés, even if you discount her string of passive-aggressive and racially insensitive remarks. “I know I can’t complain about anything anymore because, well, I’m white,” the undergrad sulks, before declaring that she’s “working like a slave” — “no offense,” she quickly adds — to pay off her tuition.

To be fair, Ms. Morisseau provides other characters with their own quirks and foibles, and the director, Stori Ayers, has the actors mine their humor and poignance. Andrea Patterson breathes boisterous life into the role of LuAnne, a slave who has been driven to betray herself and others, and brings gravity and sass to the part of Jade, one of Sandra’s colleagues — who, like Luanne, feels compelled to compete with another black woman for even a sliver of the respect and justice she deserves.

Elijah Jones also does supple double duty, playing Sara’s brother, Abner, a runaway slave turned Union soldier; and Malik, a gifted, ambitious student of both Sandra and Jade. In an exchange that grows increasingly heated, Sandra accuses her fellow professor of coddling Malik. Jade responds that the black students at their institution “seem to feel more nurtured by me than by you.”

In between scenes, these players shimmy out of Ari Fulton’s period costumes and into contemporary garb, as soulful original music by Craig “Seejai” Erquhart and Brian Erquhart of 44 Bang and Jimmy “J.” Keys shares time with old recordings of “Dixie” and “Oh! Susanna” — the latter showcasing an egregious original lyric that’s bound to make some unsuspecting Stephen Foster fans squirm.

If “Confederates” makes daunting connections between Foster’s era and our own, Ms. Morisseau, who contributed lyrics for one of the new songs, ultimately sees and celebrates the possibility of progress. And through this play’s pair of inspiring heroines, she makes it impossible for us to do otherwise.