this isn't naive stuff (anti-marxist history) but more about how choosing specific technical lines of development might be the ultimate influence, viral meme etc -- so examples include
The Webster family bring about humanity's replacement by a society of smart dogs and robots.
The Kwizts Haderach controls all the Spice in the universe.
Asimov's Foundation (at least 1.5 booksworth)
Hari Seldon's ghost manages 1000 years of the Empire's replacement.
Watson' Jonah Kit
People chose to believe a purposeless Universe, so the Whales leave to go to a better one.
Vonnegut's Cats Cradle
Felix Hoenikke creates Ice Nine. Lionel Boyd Johnson creates Bokononism
L Ron makes up some truly daft stuff, that makes Pastafarianism look pretty sane.
add yours here...