During the Harding administration, a stop-gap immigration measure was passed by Congress in 1921 for the purpose of slowing the flood of immigrants entering the United States.
A more thorough law was signed by President Coolidge in May 1924. It provided for the following:
The quota for immigrants entering the U.S. was set at two percent of the total of any given nation`s residents in the U.S. as reported in the 1890 census;
after July 1, 1927, the two percent rule was to be replaced by an overall cap of 150,000 immigrants annually and quotas determined by "national origins" as revealed in the 1920 census.
This didn't limit total immigration but capped the number from certain countries.
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