The Golden Age of Freethought is a term sometimes used to describe the limited vogue for freethinking that developed in the late 19th-century United States. It began around 1870 and lasted at least through the end of the century; author Susan Jacoby places the end of the Golden Age at the start of World War I. The Golden Age was encouraged by the lectures of Robert G. Ingersoll, the popularization of Charles Darwin’s Origin of Species, the push for woman’s suffrage, and other political, scientific, and social trends that clashed with religious orthodoxy and caused people to question their traditional ideas about the world.