What are some primary sources for Chinese restaurants?

I am currently working on a research paper on the history and development of Americanized Chinese food and restaurants, but finding primary sources has been a challenge.

I currently have a few cookbooks, restaurant menus, and Youtube videos with interviews to work with, but I really need numerical data. I would like to know the number of Chinese cuisine restaurants from between the 1870's to the 1950's or so in someplace in California. The records on don't go to that time and I have tried everything from the Smithsonian research website to but can't seem to find small business data from that time era.

A secondary piece of interest is that one of my cookbook sources appears to be written for an American living in China and spares no pity on instructing the reader how to avoid the filth of China when they cook. This book must have been written for a market, but I can't find anything about Americans migrating to China anywhere. Thoughts?

Watch the video: Amazing Foods You Never Thought To Order At Chinese Restaurants (January 2022).