Each year, the United States Census Bureau produces and publishes estimates of the population for the nation, states, counties, and state/county equivalents. The Census Bureau estimates the resident population for each year since the most recent decennial census by using measures of population change. The resident population includes all people currently residing in the United States.
The Census Bureau produces the estimates using a “top-down” approach. Given that it is generally more reliable to estimate the change of a larger population, they begin by estimating the monthly population at the national level by age, sex, race, and Hispanic origin. They then produce estimates of the total annual populations of counties, which they sum to the state level. With the national characteristics, state total, and county total estimates created, they produce estimates of states and counties by age, race, sex, and Hispanic origin.
The 2010 Census allowed for responses that included one or more of the race groups defined by the Office of Management and Budget (OMB) in 1997: White; Black or African American; American Indian and Alaska Native; Asian; and Native Hawaiian and Other Pacific Islander. It should be noted that Hispanic origin is considered an ethnicity, not a race, so that Hispanics may be of any race.