The United States Census Bureau's official population counts, as I've said, use very broad groups to categorize ethnicities which is not reflective of just how many groups of people live in the United States. Korea has an idea of how many Koreans are living in the United States currently [1] and you can probably type just about any sort of ethnicity, nationality, or race, and find some estimates or information about their presence in the United States. The Census Bureau does perform (unofficial) surveys that can give you a glimpse of the demographics in the US [2] [3] as well.

We have the largest population of immigrants in the world [4] and the nation is comprised almost entirely of non-indigenous people. The fact that the US is incredibly diverse is not controversial to anyone that is even modestly informed.

[1] https://www.mofa.go.kr/www/wpge/m_21509/contents.do

[2] https://www.census.gov/data/tables/2000/dec/phc-t-43.html

[3] https://archive.ph/20200212212204/http://factfinder.census.g...

[4] https://www.pewresearch.org/fact-tank/2020/08/20/key-finding...