Emigration
Many Chinese immigration records are in the National Archives at Seattle. These may include pictures and other documents. Must be a blood relative to access them if they are less than 100 years old.
Chinese Exclusion Act Cases are available in the National Archives catalog. Search for "All" records or "Online records" [See Chinese Exclusion Act on Wikipedia]. Information relating to materials held by NARA regions on Chinese Emigration may be found in NARA Reference Information paper 99 "Chinese Immigration and Chinese in the United States".
On the above website do a "Digital Copies" Search under "Chinese Emigration" to find additional online images of Chinese immigrants (papers and photographs) many housed in San Bruno, California.
National Archives in Chicago
Alphabetical list of Chinese exclusion case files: https://www.archives.gov/chicago/finding-aids/chinese-files-st-paul.html
https://www.archives.gov/chicago/finding-aids/chinese-files-chicago.html
Ancestry.com
GENEALOGIES
Thatcher, Melvin P. Chinese Genealogies at the Genealogical Society of Utah. [FHL 951 D23c].
HISTORICAL RECORDS
Collection in the Family History Library by family name: https://familysearch.org/search/collection/1787988.