The biggest change in this year’s census was in racial classification. Enumerators were instructed to no longer use the "Mulatto" classification. Instead, they were given special instructions for reporting the race of interracial persons. A person with both white and black ancestry (termed "blood") was to be recorded as "Negro," no matter the fraction of that lineage (the "one-drop rule"). A person of mixed Black and American Indian ancestry was also to be recorded as "Neg" (for "Negro") unless he was considered to be "predominantly" American Indian and accepted as such within the community. A person with both White and American Indian ancestry was to be recorded as an Indian, unless his American Indian ancestry was small, and he was accepted as White within the community. In all situations in which a person had White and some other racial ancestry, he was to be reported as that other race. Persons who had minority interracial ancestry were to be reported as the race of their father.
For the first and only time, "Mexican" was listed as a race. Enumerators were instructed that all persons born in Mexico, or whose parents were born in Mexico, should be listed as Mexicans, and not under any other racial category. But, in prior censuses and in 1940, enumerators were instructed to list Mexican Americans as white.
The Supplemental American Indian questionnaire was back, but in abbreviated form. It featured a question asking if the person was of full or mixed American Indian ancestry.
Read more about this topic: Race And Ethnicity In The United States Census, Brief Overview of Race and Ethnicity in The U.S. Census' History