I dunno... 1790 Naturalization Act says only white people could become citizens. Sounds like they were friendly towards immigration from very specific countries.

Roosevelt's 1915 Americanism address also reveals this:

https://www.gutenberg.org/files/68152/68152-h/68152-h.htm

He says americanism "is a matter of the spirit and of the soul". In the very next paragraph, the so called "hyphenated americans" are condemned. This is perfectly reasonable.

However, note the examples used:

  German-Americans
  Irish-Americans
  English-Americans
  French-Americans
  Scandinavian-Americans
  Italian-Americans

The implication is only the souls of white europeans were eligible for americanization.

There is even legal precedent for this:

https://en.wikipedia.org/wiki/United_States_v._Bhagat_Singh_...

In 1923, the supreme court decided an indian was not eligible for citizenship because he was not white.

So arguably the US was a white ethnoatate from the very beginning. This stuff only really went away after the 1965 Hart-Celler Act, just over half a century ago.