Do you find the historical myth that there was little Atheism...

[The Mikado]

I haven't heard much of that, though I have heard the almost-as-stupid argument that there was little-to-no Atheism pre-mid-19th century.  Then again, most of the people I talk to are aware of Karl Marx and Sigmund Freud, at least.

[The Mikado]

It depends on a lot of factors, but Jacobins (both French and their English and American wannabes) had a large proportion of atheists in their ranks (many inspired by Paine's The Rights of Man).  Freethought and Unitarianism had long pedigrees, though not quite athiest.  Edward Gibbon, for example, was tremendously down on Christianity and he was an extremely prominent author.