Felicity Jones in 2015, left, and Ruth Bader Ginsburg in 1950. (Ian Gavan/Getty Images/James Madison High School Yearbook)

In the first trailer for “On the Basis of Sex,” the film about Ruth Bader Ginsburg’s legal fight for equal rights, British actress Felicity Jones jumps into the title role speech-first.

“You don’t get to tell me when to quit,” says Jones-as-Ginsburg in one of several Big Speech Moments in a newly released sneak peek of the “inspired by a true story” film. Jones has said in interviews that she was a “crazy person” about getting Ginsburg’s borough-specific New York accent just right. “I was full Ruth Bader Ginsburg,” she told the Hollywood Reporter, never breaking from her character while on set.

To really do a Brooklyn accent, according to experts, you have to be able to say “coffee” and dog” with the drawn out “aw” sound that transforms those words into “cawfee” and “dawg.” Or in Jones’s case, “laaaws” — more specifically the nearly 200-such laws that differentiated on the basis of sex and which Ginsburg fought to change.

“On the Basis of Sex,” which stars Armie Hammer as a ridiculously handsome Marty Ginsburg, Kathy Bates perfectly cast as women’s rights activist Dorothy Kenyon, and an almost unrecognizable Justin Theroux as ACLU lawyer Mel Wulf, is the latest offering in a long line of Ginsburg cultural swag. There’s “RBG,” the recent documentary about the Supreme Court justice; a children’s book; and a guide to the feminist icon’s physical workout, to name a few.

The new film, set to hit theaters at Christmastime, follows Ginsburg as she takes the case Charles E. Moritz v. Commissioner of Internal Revenue — in which an unmarried man was denied a tax deduction for taking care of his mother — to the Tenth Circuit Court of Appeals.

Correction: An earlier version of this article referred to the case represented in the film as Weinberger v. Wiesenfeld. According to a representative of Focus Features, the case covered in the movie is Charles E. Moritz v. Commissioner of Internal Revenue. The article has been updated.