>California was almost empty when it was annexed into the US. Disease etc. Immigration from the rest of the English-speaking US completely dwarfed what was left.

>Almost 100% of Spanish-speaking Californians have come in the past 50-70 years. Basically none have historical roots to California.

Correct. I go into more detail on why this is the case elsewhere. <https://news.ycombinator.com/item?id=38415835>