During the 19th Century, the United States boasted of the most Biblically literate population the Western world has ever known. Hence so many young men being given some rather intense Bible names like "Abraham" (Lincoln) and "Thaddeus" Stevens, etc...
As Lincoln stated in his second inaugural:
Both read the same Bible and pray to the same God, and each invokes His aid against the other. It may seem strange that any men should dare to ask a just God's assistance in wringing their bread from the sweat of other men's faces, but let us judge not, that we be not judged. The prayers of both could not be answered. That of neither has been answered fully. The Almighty has His own purposes...
But something about Nietzsche's writings in particular were...violent and self-destructive in nature.
Bingo! And one could argue that Darwin pushed belief in natural selection not so much to "prove" God doesn't exist or change the nature in which we think of or origin, but to try to slow down the growing abolitionist movement that the church was pushing. The thinking was that if you undermine the Christian belief that God exists, you undermine their push to love God and love your fellow man by freeing God's creation from slavery.