When Darwin's theory became established at the end of the 19th century as the only theory besides God to explain life, 100 years after Lyell had already explained the planet Earth without God, that is when we see a big historical shift toward atheism--Nietzsche, Marx, Freud, Ingersoll--and each of them influenced a helluva lot of people with antipathy toward religion.
Marx wrote the Communist Manifesto a decade before Darwin wrote the Origin of Species.
Nietzsche rejected Darwinism:
I see all philosophers and the whole of science on their knees before a reality which is the reverse of the struggle for life as Darwin and his school understood it- that is to say, wherever I look, I see those prevailing and surviving, who throw doubt and suspicion upon life and the value of life.- The error of the Darwinian school became a problem to me: how can one be so blind as to make this mistake?
The reasons that turned Ingersoll from religion you have already quoted.
Of Freud's religious opinions and, for that matter, his grasp of evolution, I know nothing.