'On the basis of sex' trivia and fun facts
Pauli Murray
When Ruth is preparing to appear in front of the federal appeals court, she practices in front of a panel of mock judges, including her former professor Gerald Gunther and the legal scholar, civil rights activist, and pioneering Episcopal priest Pauli Murray. During the practice session, Murray assumes the identity of a male judge; in fact, in Rosalind Rosenberg's 2017 biography "Jane Crow: The Life of Pauli Murray," Rosenberg reveals that Murray was in fact what we would today characterize as transgender--she identified as male.
Cameo
Ruth Bader Ginsburg: She appears as herself at the very end.
Related
Daniel Stiepleman - the writer of the film - is Ruth Bader Ginsburg's nephew.
Age
Although she plays their daughter, Cailee Spaeny is only 13 years younger than Felicity Jones and 11 years younger than Armie Hammer.
Different protagonist
In the first years of development of the film, Natalie Portman was going to play the part of Ruth Bader Ginsburg, until she abandoned the project and Felicty Jones was casted for the role.
Question
Following an argument between Jane and Ruth, Jane retreats to her room and cranks up her stereo. Martin goes in to her room to comfort her, turns down the stereo, and tells her how Ruth grew up being taught to question everything. The song Jane was playing was "Question" by The Moody Blues.
Exceptional
The French title for the film is 'Une Femme d'Exception' which translates to 'An Exceptional Woman'.
Against her
At the end they say that 3 people voted against Ruth Bader Ginsburg for the Supreme Court. One of the men was North Carolina Senator Jesse Helms who was a conservative republican.