Hi OP, this is a great question, please have gold.

As a follow-up question… I live in San Francisco, CA, and I’ve always been told that the Chinatown here was founded by the Chinese immigrants in the second half of the 19th century mostly running laundry businesses, building the railroad, and working as prostitutes.

To what extent is this true, and where could I read more about this? If this is true, were these occupations specific to San Francisco, or were they similar in other cities?

Edit - typos.