MsPOSSOM - Population Explorer

MsPOSSUM's Population Explorer

Explore Census county population estimates across all states and territories by year, geography, sex, race, ethnicity, and standard or custom age bands.

Experimental module. This Population Explorer module is still under development. Treat all results as experimental and cross-check values with reliable source materials before using them for decisions, publications, or reporting.

Build a query

Pick years, geography, and population characteristics in the Data Selection panel.

Press GO!

Results appear in the Table, Plots, Pyramid, and Map panels.

Available Filters

Filter	Options
Data Source Override	Auto, Census PEP, SEER
Years	Census PEP: 2011 - 2025; SEER: 1990 - 2024
States	50 states + D.C.
Counties	All counties/county equivalents
Mississippi Regions	Central, Delta, North, South
Mississippi Districts	D-I through D-IX
Race	Source-specific Census PEP or SEER categories
Ethnicity	Hispanic, Non-Hispanic
Sex	Male, Female
Age (10-yr)	00-04, 05-14, 15-24, ... 75-84, 85+
Age (5-yr)	00-04, 05-09, 10-14, ... 80-84, 85+
SEER Ages	Single-year ages or custom ranges such as 00-04, 05-17, 18-64, 65-90

About the Population Explorer

Overview

The Population Explorer is an interactive dashboard for examining county-level population estimates across all states and D.C. It draws on Census PEP annual estimates for standard age bands and SEER single-age estimates for custom age requests, allowing users to filter, compare, and visualize population patterns across states and counties.

Data

Census PEP covers 2011 through 2025 with 5-year and 10-year age bands. SEER covers 1990 through 2024 with single-year ages that can be aggregated into user-defined ranges. Race categories differ by source, so the sidebar shows source-specific race and ethnicity choices.

Methodology & Definitions

Population Estimates

County-level Census PEP estimates are produced annually by the U.S. Census Bureau's Population Estimates Program. SEER adjusted county population estimates are maintained separately and provide single-year ages for custom grouping.

Geographic Classifications

Region: Mississippi counties are grouped into four regions: Central, Delta, North, and South.
District: Nine public health districts (D-I through D-IX) used by the Mississippi State Department of Health.
Urban/Rural (HRSA): Metropolitan vs. non-metropolitan designation based on OMB metro area definitions.
Urban/Rural (NCHS): Six-level classification from the National Center for Health Statistics ranging from large central metro to non-core.

Race & Ethnicity

Race categories are source-specific. Census PEP includes six race categories in this app; SEER uses bridged race categories: White, Black, American Indian/Alaska Native, and Asian/Pacific Islander. Ethnicity is reported separately as Hispanic or Non-Hispanic.

External data sources and related tools are available from the Resources menu in the top navigation bar.