Question number 13 (see below) on the 1990 United States Census long form asked people to write in their ancestry or ethnic origin. 5% wrote simply "American." The most frequently reported ancestry in the US was German. Nearly one fourth of the American people (58 million) considered themselves to be of German or part German ancestry. The total US population in 1990 was 248,709,873.
The Top Fifteen Ancestry Groupsas reported in the 1990 census:
(numbers have been rounded)
Question 13 stated:
What is this person's ancestry or ethnic origin?
(See instruction guide for further information.)
(For example: German, Italian, Afro-Amer., Croatian, Cape Verdean, Dominican, Ecuadoran, Haitian, Cajun, French Canadian, Jamaican, Korean, Lebanese, Mexican, Nigerian, Irish, Polish, Slovak, Taiwanese, Thai, Ukrainian, etc.)
The Instructions for Question 13 stated:
Print the ancestry group. Ancestry refers to the person's ethnic origin or descent, "roots," or heritage. Ancestry also may refer to the country of birth of the person or the person's parents or ancestors before their arrival in the United States. All persons, regardless of citizenship status, should answer this question
Persons who have more than one origin and cannot identify with a single ancestry group may report two ancestry groups (for example, German-Irish).
Be specific, for example print whether West Indian, Asian Indian, American India. West Indian includes persons whose ancestors came from Jamaica, Trinidad, Haiti, etc. Distinguish Cape Verdean from Portuguese; French Canadian from Canadian; and Dominican Republic from Dominica Island.
A religious group should not be reported as a person's ancestry.
Source: US Bureau of the Census: Census Questionnaire Content, 1990 CQC-14US (issued Feb 1995)...
Download this PDF Ancestry Questionnaire for more details about the ancestry of the population of the United States in 1990.