This was know as The Golden Age of Freethought. It was generally recognized to have lasted from the end of the American Civil War until the end of World War I. With the beginning of World War I many governments, including the United States, passed laws against free speech and began regulating speech more closely. However, it was not World War I that brought an end to the Golden Age of Freethought, but rather it was the Bolshevik Revolution, which elevated anti-religious ideas to a new level of threat against the established social order. Religious criticism in the Freethought era is distinguished from the earlier Enlightenment era by being much less academic and much more popular, it's when religious criticism moved into normal society?