County research and study
Allen County, Kentucky
Use a county profile as a source-reading exercise or the geographic context for your own research. Keep the county FIPS identifier with your notes so that similarly named places in different states are not mixed.
Identify the right place
Allen County is a county or county equivalent in Kentucky. Its five-digit FIPS code is 21003; preserve the leading zero when storing county codes as text. The Gazetteer lists 8.14 square miles of water and a representative point at 36.75077, -86.192458. That point identifies the geography; it is not a street address or a site boundary.
Open this county in Census data · Download this county as JSON
County research and study checklist
- Write a specific research question before summarizing sources.
- Separate a Census estimate from an exact count or a current forecast.
- Cite the dataset and year next to every number in your notes.
The figures describe the county; they are not an evaluation of schools or an estimate of educational outcomes.
Sources and interpretation
Geography: 2025 U.S. Census Gazetteer. Population: Vintage 2025 estimates, July 1, 2025. County equivalents include parishes, boroughs, independent cities and planning regions. Puerto Rico population is not supplied by this population file.
Population is an estimate, not a live count. Gazetteer land and water measures describe the geographic area; they do not measure service availability, households, businesses or market demand. Match the FIPS code and source vintage when joining another dataset.
More county references in Kentucky
- Adair County
Kentucky · FIPS 21001
19,423 residents · 2025 estimate
- Anderson County
Kentucky · FIPS 21005
25,225 residents · 2025 estimate