The Chinese Exclusion Act of 1882 was used to keep laborers out of the U.S. before WWII. It was repealed over 70 years ago.
The paper trails they are using to do their genealogies contain a lot of fabrications on names and relationships. They needed to be inventive to be able to enter the country. Can you imagine trying to uncover the truth? Although I think we’ve all had to deal with erroneous information.