I would posit that the fact that we inhabited a New World that had been entirely unknown to the Old, made us more receptive to the idea that there could be other words with sentient life.
Ok, but down in Mexico and other parts of Latin America SciFi isn’t very big. Canada also doesn’t have much in the way of a SciFi scene independent from the United States.
Canada doesn't have an independent Anglophone culture from that of the United States. At most, it's a regional subculture, like Southern literature is a subculture.
Latin America went more for magical realism, which to a large degree reflects the syncretism of Catholicism and native religions.
Ok, but why is these elements big here? We managed to take in very superstitious immigrants such as rural Irish and South Italian communities that are both very spiritual and superstitious in believing in minor spirits and having strong folkloric tradition.
Why did it emerge so early in the 1830s when advances in Astronomy and Psychology much bigger in western and Central Europe with far more religious contact and urbanization increasing the need for Scientism.