Some quotations

From The Atlantic:

In a major speech in Alabama in 1921, President Warren Harding said there is “a fundamental, eternal, inescapable difference” between the races. “Racial amalgamation there cannot be.”

Calvin Coolidge wrote, “There are racial considerations too grave to be brushed aside for any sentimental reasons. Biological laws tell us that certain divergent people will not mix or blend,” in a 1921 article in Good Housekeeping.

Some guy named Adolph Hitler told The New York Times, "It was America that taught us a nation should not open its doors equally to all nations.” Another Hitler comment, the U.S. “simply excludes the immigration of certain races. In these respects America already pays obeisance, at least in tentative first steps, to the characteristic völkisch conception of the state.”