Race and ethnicity in the United States Census, as defined by the Federal Office of Management and Budget (OMB) and the United States Census Bureau, are self-identification data items in which residents choose the race or races with which they most closely identify, and indicate whether or not they are of Hispanic or Latino origin (ethnicity).
The racial categories represent a social-political construct for the race or races that respondents consider themselves to be and "generally reflect a social definition of race recognized in this country." The OMB defines the concept of race as outlined for the US Census as not "scientific or anthropological" and takes into account "social and cultural characteristics as well as ancestry", using "appropriate scientific methodologies" that are not "primarily biological or genetic in reference." The race categories include both racial and national-origin groups.
Race and ethnicity are considered separate and distinct identities, with Hispanic or Latino origin asked as a separate question. Thus, in addition to their race or races, all respondents are categorized by membership in one of two ethnicities, which are "Hispanic or Latino" and "Not Hispanic or Latino".
In 1997, OMB issued a Federal Register Notice which provided revised racial and ethnic definitions. OMB developed race and ethnic standards in order to provide "consistent data on race and ethnicity throughout the Federal Government. The development of the data standards stem in large measure from new responsibilities to enforce civil rights laws." Among the changes, OMB issued the instruction to "mark one or more races" after noting evidence of increasing numbers of interracial children and wanting to capture the diversity in a measurable way, and after having received requests by people who wanted to be able to acknowledge their or their children's full ancestry rather than identifying with only one group. Prior to this decision, the Census and other government data collections asked people to report only one race.
The OMB states that “many federal programs are put into effect based on the race data obtained from the decennial census (i.e., promoting equal employment opportunities; assessing racial disparities in health and environmental risks). Race data are also critical for the basic research behind many policy decisions. States require these data to meet legislative redistricting requirements. The data are needed to monitor compliance with the Voting Rights Act by local jurisdictions."
"Data on ethnic groups are important for putting into effect a number of federal statutes (i.e., enforcing bilingual election rules under the Voting Rights Act; monitoring and enforcing equal employment opportunities under the Civil Rights Act). Data on Ethnic Groups are also needed by local governments to run programs and meet legislative requirements (i.e., identifying segments of the population who may not be receiving medical services under the Public Health Act; evaluating whether financial institutions are meeting the credit needs of minority populations under the Community Reinvestment Act).”
In 1790, first official year of the U.S. Census, the following questions were asked, four of which had racial implications: