The ways that race and ethnicity have been classified in data collection have changed over time and across settings. This includes classification in federal data collection systems, as we will detail below, but also data collected through record systems outside the purview of the federal government. This lack of consistency across settings or across methods for collecting data on race and ethnicity can pose problems for the interpretation of such data. For example, the population of American Indians is reported to have tripled between the 1960 and 1990 censuses, an increase that cannot be explained by migration or demographic changes (Sandefur et al., 2002) but that may be attributable to variations in self-identification or in the federal definition of that identity.
The federal government has been collecting data on race since the first U.S. census in 1790, with data on ethnic background added in later censuses. Census standards for racial classification have changed greatly over time. In the first census, enumerators classified free residents as white or “other,” with slaves counted separately. Table 3-1 gives a history of how race and ethnicity have been classified in each census since 1790. Over time, as the nation’s population became more diverse and as individual ethnic groups identified themselves, more categories were added and occasionally some were dropped. Some changes worth noting in recent decades include the addition of a question on Hispanic ethnicity as a separate item in 1977, and in 2000 the option for allowing individuals to identify with more than one racial group.
No federal standards for the collection of data on race and ethnicity existed until 1977, when the Office of Management and Budget (OMB) developed and issued a set of standards, called Statistical Directive Number 15, for the collection of these data. These standards were developed to provide consistency in defining race and ethnicity for civil rights legislative use, monitoring equal treatment, and other public policy uses (NRC, 2004). The Statistical Directive Number 15 classification system included four categories for race (white, black, Asian or Pacific Islander, and American Indian or Alaska Native) and two for ethnicity (Hispanic and non-Hispanic). Self-report was established as the preferred method of collecting data, and respondents were instructed to choose only one race and one ethnicity.1