This classification refers to the person's marital status at the time of enumeration. Persons classified as married comprise, therefore, both those who have been married only once and those who remarried after having been widowed or divorced. The enumerators were instructed to report persons in common-law marriages as married and persons whose only marriage had been annulled as single. Separated persons are included in the count of married persons.

The three major race categories distinguished in this report are white, Negro, and other races. Among persons of other races are American Indians, Japanese, Chinese, Filipinos, Koreans, Asian Indians, and Malayans. Negroes and persons of other races taken together constitute nonwhite persons. Persons of Mexican birth or descent who are not definitely Indian or other nonwhite race are classified as white. In addition to persons of Negro and of mixed Negro and white descent, the category Negro includes persons of mixed Indian and Negro descent unless the Indian ancestry very definitely predominates or unless the person is regarded as an Indian in the community.