Clarence Seward Darrow (1857-1938) was an American atheist-leaning agnostic criminal lawyer. In July 1925 he defended schoolteacher John T. Scopes in the famous Scopes evolution trial in Dayton, Tennessee. Although many think Darrow won that case, he and Scopes lost the trial to the prosecution’s William Jennings Bryan when the jury found Scopes guilty of teaching evolution in violation of state law. Darrow was a skilled orator and debater, who read Nietzsche, Tolstoy, and Voltaire, always fought against capital punishment, and included excerpts of famous poems in his trial summations. People who knew him felt confident he had bribed witnesses and jurors in some of his cases, and in 1912 he was charged, though acquitted, with jury tampering. 
Clarence Darrow was born near Kinsman, Ohio, on Saturday April 18, 1857. His father, Amirus Darrow, was the village undertaker and coffin maker. As a teenager, the young Darrow took part in town debates, and honed his debating skills to the point where he never lost a debate. He developed necrophobia (fear of death) in his childhood, which may explain his lifelong fight against the death penalty.  None of his clients were ever executed.
Darrow the lawyer
Darrow began his law career in Youngstown, Ohio. He became a member of the Ohio bar in 1878, and in 1887 moved to Chicago, Illinois, where he worked as a lawyer for the railroad company. In 1896, he attended the Democratic National Convention and listened to a young member of Congress from Nebraska, William Jennings Bryan, give his famous "Cross of Gold" speech. Although Darrow criticized the speech, he admitted later that he had never known a speech to influence an audience as much as Bryan's did.
After defending various murder cases and other criminal cases, Darrow found himself on trial in Los Angeles in 1912. He was charged with trying to bribe a juror in a case that involved bombing the Los Angeles Times building that killed 21 people. The jury acquitted Darrow, although according to law professor Doug Linder and others, Darrow "most likely" was guilty. 
In 1925, Tennessee passed the Butler Act, which made it illegal to teach evolution in any publicly funded teaching institution in the State. The American Civil Liberties Union (ACLU) decided to challenge this law, and recruited schoolteacher and part-time football coach John Scopes, from Dayton, Tennessee, to admit teaching evolution and to stand trial in the ACLU’s test case.
Clarence Darrow volunteered to head Scopes’ defense, and William Jennings Bryan volunteered to prosecute the case. Darrow’s antireligious attitudes initially worried the ACLU, who thought it may turn the trial into an attack on religion, which could damage their case. Some were also concerned that Darrow had recently defended two young thrill-killers, Nathan Leopold and Richard Loeb, and that this could obscure the point of the Scopes case. But Scopes wanted Darrow, so Darrow took the role on the defense team.
A thousand people jammed Dayton’s Rhea County Court House when the Scopes trial began in sweltering weather on Friday July 10, 1925. Around town, colorful banners decorated the streets, chimpanzees amused onlookers, and the Anti-Evolution League sold copies of Bryan’s books.
Darrow grills Bryan
On day 7 of the trial, Judge Raulston asked Darrow if he wanted to present any more evidence. In an extraordinary decision, and one that turned the tide against the prosecution, Darrow called William Jennings Bryan to the stand as an expert on the Bible.
Darrow bombarded Bryan with questions designed to undermine the literalist view of the Bible. He asked Bryan whether the whale that swallowed Jonah was a whale or a fish. He asked about the sun standing still for Joshua, how old the earth is, questions about Noah’s Flood and Buddha, questioned the accuracy of miracles in the Bible, and labored over many biblical matters.
Bryan did well with some answers, but faltered on others—especially when he said the days of creation may be long periods of time and implied that Bible chronology may not be accurate. This gave Darrow a loud drum to beat: If the Bible is wrong then it should not be used as the basis for a law preventing schools from teaching evolution. Although the truth of the Bible did not hinge on Bryan’s understanding of it, many at the trial looked to Bryan for right answers, which they did not always get.
Many people did not pick up on how deceptive Darrow had been in the courtroom, using fraudulent Scripture references to denigrate the Bible’s value. Darrow said: "Are your mathematics good? Turn to I Elijah ii." [A non-existent book of the Bible.] "Is your astronomy good? See Genesis Chapter 2, verse 7." [This verse has nothing to do with astronomy. It is about the creation of man.] "Is your chemistry good? See—well, chemistry, see Deuteronomy iii-6." [This verse is about the battle with King Og, not about chemistry.]
Darrow lost the trial, but Bryan lost the confidence of many fundamentalists. Darrow died on Sunday March 13, 1938 at the age of 80, and his ashes were scattered on the waters of Chicago’s Jackson Park Lagoon.
Agnostic or atheist?
Clarence Darrow called himself an agnostic. He said, "I am an agnostic; I do not pretend to know what many ignorant men are sure of."  Yet his antireligious beliefs have long led atheists to claim him as one of their own.  Atheist Madalyn Murray O’Hair once wrote, "Clarence Darrow, was an Atheist ..." 
- Professor Douglas O. Linder Who is Clarence Darrow?
- Geoffrey Cowan The American Lawyer A Man For Some Seasons
- Notable biographies
- Spartacus Net Darrow biography for schoolchildren
- Tennessee vs. John Scopes
- William Jennings Bryan
- John Scopes
- American Civil Liberties Union
- History of Creationism