The 2020 US Census asked questions about the race and ethnic composition of every American. Based on current guidelines, each person was asked which race they identify as. In a separate question, they were asked if they were of Hispanic or Latino origin. Both of those questions had a write-in field for “origin”, enabling respondents to narrow in on the specifics of their ethnicity. For example, I answered “White” as my race and “German” as my origin, since most of my ancestors (that I know of) came from Germany. Respondents could indicate more than one race.
Even though the census frames the questions in terms of ‘race’ and ‘ethnicity’, I’ll use the term ‘heritage’ instead, defined as “something that is passed down from preceding generations; the status acquired by a person through birth”. There were no restrictions for the “origin” field – respondents could write in whatever they wanted. Also note that this is completely self-reported – there was no verification or test of the answer. We’re just getting the result of how people describe their heritage.
The census reported results in six main categories: White, Black or African American, Asian, Hispanic, American Indian or Alaskan Native, and Hawaiian/Pacific Islander. Within each of these there are subcategories. For example, White has European, North African, and Other. Within each of the subcategories are detailed origins. White European has 67 possible origins, from Albanian to Welsh (the most common is English, over 46 million people; the least common is Faroe Islander, of which there are 272 across the whole country). Across the races and ethnicities, there are hundreds of possible origins/heritages.
This link will open up a map of the US that visualizes the relative frequency of a heritage at the state or county level. Pick a specific Heritage to see its distribution – from dark blue (highest frequency) to white (lowest). You can click on a county or state to see the actual percentage of that heritage. I recommend using a PC/laptop, or at least a tablet – the bigger the screen, the better (depending on the size of your screen, rotating your tablet/phone might help).
[Be aware that the color display is always relative – dark blue means the highest percentage of that particular heritage. This can vary widely from heritage to heritage. For the more obscure heritages, dark blue doesn’t mean “common”, it means “rare, but just not as rare as everywhere else”.]
Anyway, have a look.