...than in northern New England and Utah/Mormon country since the 1980 census?
My guess is: the South didn't get much immigration from the 19th century onward and whites (the great majority with British roots) defined themselves more racially than along ethnic lines. In contrast New England received French Canadian and Irish immigrants from which :old stock" New Englanders distinguished themselves. Meanwhile it seems Utah's development depended as much on direct immigration from Britain as it did on Western migration of Americans with colonial roots.
Lower educational attainment in the South likely played a role too.
The question has changed over time.
Prior to 1980, the Census Bureau asked for place of birth of a person's parents, and reported statistics for "foreign stock", those born abroad, or whose parents were born abroad. If someone's grandparents were born in the USA, they were native stock.
After immigration declined around 1920, there were fewer persons born abroad, or whose parents were born abroad. Typical immigrants are in their 20s, with perhaps small children. By 1970 there would be few foreign born under 70, and of foreign stock under 40-50s.
The ancestry question appears to have been an effort to replace a question that was of less value as almost everyone said USA, USA, USA. Growing up, my family used "nationality" to mean "ancestry". There was no reason to say American, since everyone was an American, and why would someone ask a question that they knew the answer to? Later, I remember a Brit who was amused that Americans would answer "Irish or Italian or English".
The 1980 form is the only one to give "English" as an example. Some of the other examples may have been to encourage those of non-European stock to report a specific country (if someone saw "Korean", they could infer that "Japanese" was also a proper response).
The Census may not known what to expect in response. In their 1980 statistics, they include data for specific combinations of three, typically with pairs of the Big 3: English, Irish, German, plus some other.
By 1990, "English" had been removed. The question had been modified to express that it meant ancestry or ethnicity. The Census Bureau was either attempting to foment secession in Eastern Europe, or didn't want a mix of Yugoslav, Croatian and Serb. Perhaps Slovaks might put Czechoslovakia, because they thought that was what the Census Bureau might be asking. In any case, Slovak ancestry declined after 1990. This may be due to dying off of persons whose parents were born in Austro-Hungary, and might have known their ancestry. Later arrivals might have indicated Czechoslovakian, and there wouldn't be new arrivals from Slovakia. I think Cape Verdean may have been a deliberate effort to discourage responses of Portuguese. Haitian and Dominican may be to encourage a distinction from African American.
If one sees an example of "African American", they might think that they were "Irish American", or "German American", and simply put Irish or English. But I don't think "English American" was ever used, especially since there was a deliberate effort to distinguish USA from GB as a country, which would be much stronger than in Canada or Australia, for example. Columbus was promoted as the discoverer of the New World, since he, unlike Cabot, was not English. And other persons may put "American" as a contrast to "African American"
The question is difficult to ask, since the Census Bureau really doesn't know what information it is seeking. It may have little official purpose, other than possible discrimination.
The list dropped from 21 to 16, as German, Croatian, Ecuadoran, Cajun, Irish, Slovak, and Thai, were dropped, and Cambodian and Norwegian were added.
The Census may have decided that they were inducing responses of German and Irish. This may have been an attempt to encourage respondents to think that they were seeking more information about more exotic ancestries.
Perhaps there was a feeling that Italian and Polish faced some residual discrimination, or perhaps there is stronger ethnic identification. Someone whose ancestors immigrated prior to the Civil War likely have 50 or so such ancestors, and there have been subsequent migration westward, with mixing and identification with the city or state replacing a country-ancestry. Immigrants prior to WWI, would have about 1/8 as many immigrant ancestors.
The list was somewhat de-alphabetized, and respondents were no longer expected to know what etc. meant. This might be based on a finding that some people subconsciously recognize alphabetized lists, and mixing the order may encourage each word to be read. Interesting, is the abbreviation of "African Am.". Was this because of the influence of the question on other respondents?
2005-2008
The ACS, which replaced the Long Form after the 2000 census, maintains the question from the 2000 Census.
The instruction leave some ambiguity. Someone in Mississippi is unlikely to think of themselves of being ethnically English. They don't have a Queen, don't play soccer, don't have accents. At best, they might aspire to go to Oxford for college.
