In September 1997, during the process of revision of racial categories previously declared by OMB directive no. 15, the American Anthropological Association (AAA) recommended that OMB combine the "race" and "ethnicity" categories into one question to appear as "race/ethnicity" for the 2000 US Census.
Prior to 1997, where were racial categories declared for the U.S. Census?
OMB directive no. 15