There's a bio of William Jennings Bryan (represented in the movie as "Matthew Brady") which says
In 1925, Bryan led the prosecution of John T. Scopes, a young biology teacher charged with breaking Tennessee law by teaching Darwin's theory of evolution. Squaring off against noted defense attorney Clarence Darrow, Bryan attempted in vain to defend his literal interpretation of the bible under Darrow's wilting cross examination. Humiliated and weakened by the stress of the trial, Bryan died one week after its conclusion.... while in the movie, "Matthew Brady" (portrayed as a bombastic oaf who'd be quite comfortable articulating Intelligent Design in 2005) dies in the courtroom immediately after the trial is concluded .. chalk it up to poetic license (or The Radical Right's perceived Hollywood Agenda).
Here are the major characters in the film, and the real people they represented:
Henry Drummond (Spencer Tracy) .. portraying Clarence Darrow
Matthew Brady (Fredric March) .. portraying William Jennings Bryan
Bertram T. Cates (Dick York) .. portraying John Thomas Scopes
It was hard to watch:
- the judge (Harry Morgan) and not think of Colonel Sherman Potter of M*A*S*H (TV series);
- the defendant (Dick York) and not think of Darrin Stevens of Bewitched;
- the reporter (Gene Kelley) and not think of Singing In the Rain.