For counts in intercensal years, use the population estimates when the level of detail needed is:
- total population only,
- counts for population subgroups based age, sex, basic race, and basic Hispanic origin.
The estimates are calculated by updating data from the 100% count questions in the Decennial Census using administrative data on births, deaths, and domestic and international migration.
Historically estimates are available for the nation, states, metropolitan areas, and counties. Since 2000, data is also available for cities and towns.
- Census Bureau's Population Estimates
This page has current and historic data (back to pre-1980). For some years, data are available by age groups and race. Most data is in Excel files specific to a geography.
- data.census.gov (2006 - forward)
The Population Estimates Program is listed under "Detailed Data." Annual estimates are reported for county, places, and county subdivisions starting with 2001. Note for the most current year, state level data are released ahead of estimates at lower levels.
- ICPSR
From the ICPSR collection contains a selection of population estimates files, some dating to the 1970s. Search ICPSR data holdings for the phrase "population estimates" in the title field.
- Population Estimates for Missouri and Across the U.S. (from the Missouri Census Data Center)
The MCDC republishes the annual estimates with an easy-to-use web menu. Data is reported by state, county, and Metropolitan/Micropolitan areas starting from 2000s. Totals are given by age, sex, Hispanic origin and basic race. The format is PDF.
- Regional Economic Accounts (from BEA)
This a link to the Bureau of Economic Analysis' REA page. The links under the Data heading are to their interactive reporting system. Along with the economic data, population estimates (total population only) are available for states, metropolitan areas and counties. For population choose the "Local Area Personal Income and Employment" link and then table, "Personal income and employment summary (C04)". Then follow the menus to choose geography, statistic-unit of measure (population-level), and time period (data from 1969 forward).
- U.S. Population 1969-forward (from the National Cancer Institute)
Annual county-level population estimates based on race categories are available for the total population, for 19 age groups, and for single year ages.
- U.S. Census Populations With Bridged Race Categories
Race bridging is a method used to make multiple-race and single-race data collection systems sufficiently comparable. The files at this site contain population estimates by year, county, single-year of age, bridged-race, Hispanic origin, and sex for years 1990 forward. The bridged race categories used are the four race categories specified under the 1977 standards (White, Black or African American, American Indian or Alaska Native, Asian or Pacific Islander).
- U.S. Census Population Estimates APIs