Measuring the Racial and Ethnic Composition and Diversity of the United States Population: Historical Challenges and Contemporary Opportunities

Every decennial census since the very first in 1790 has included a question on race; however, the race question in every decade has always been different in some shape or form. For example, a race category for “Mexican” was included in the 1930 Census, but there was not a formal question about Hispanic origin (i.e., “ethnicity”) on the full decennial census until 1980. Since 1980, the Hispanic origin question has also undergone changes each decade. The frequent modification to these questions reflects the difficulty inherent to measuring the fluid and complex concepts of race or ethnicity. In this paper, we review the historical challenges and contemporary opportunities with accurately measuring the racial and ethnic composition and diversity of the US population. Specifically, we provide an overview of the evolution of the race and ethnicity questions from the 1790 Census to the 2020 Census, review the U.S. Census Bureau’s efforts to measure and analyze racial and ethnic diversity for the 2020 Census, and discuss the historic updates made in 2024 for improving the measurement of race/ethnicity in Federal data collections moving forward.