In 1925, Lela V. Scopes, twenty-eight, was turned down for a job teaching mathematics at a high school in Paducah, Kentucky, her home town. She had taught in the Paducah schools before going to Lexington to finish college at the University of Kentucky. But that summer her younger brother, John T. Scopes, was set to be tried for the crime of teaching evolution in a high-school biology class in Dayton, Tennessee, in violation of state law, and Lela Scopes had refused to denounce either her kin or Charles Darwin. It didn’t matter that evolution doesn’t ordinarily come up in an algebra class. And it didn’t matter that Kentucky’s own anti-evolution law had been defeated. “Miss Scopes loses her post because she is in sympathy with her brother’s stand,” the Times reported.

In the nineteen-twenties, legislatures in twenty states, most of them in the South, considered thirty-seven anti-evolution measures. Kentucky’s bill, proposed in 1922, had been the first. It banned teaching, or countenancing the teaching of, “Darwinism, atheism, agnosticism, […]