"He went around the country," Jacoby tells NPR's Rachel Martin. "He spoke to more people than presidents. He was also an active mover and shaker behind the scenes of the Republican Party."

But Ingersoll is largely forgotten today. His crime? Speaking out in favor of the separation of church and state. Jacoby, the author of a new biography The Great Agnostic: Robert Ingersoll and American Freethought, says he promoted Darwin's theory of evolution and fought publicly against government interference in religion.

"Because of this, as The New York Times said in his obituary when he died in 1899, he couldn't run for public office even though he was a big deal behind the scenes," she says. "Because even then, although most of the Republican presidents from Lincoln on didn't even belong to a church, you still, if you were an open agnostic or atheist, could not hope to run for public office."

Ingersoll actually gave up his public career, Jacoby says, because "he thought it was more important to talk about the ways in which fundamentalist religion was a bad thing."

 

Listen to the interview at the link below.