St. Libory: Demographics & People

St. Libory's population stands at 559 people, in 255 households. Population shrank 8.7% from 612 (2022) to 559 (2024). Median age 43.3 years. (3.4y older than St. Clair County; 4.2y older than Illinois). Children under 18 are 17% of the population. Population is 96% White (non-Hispanic) and 1% Hispanic or Latino. The community is relatively homogeneous (Simpson index 0.05). 66% of households are family-led. County is losing 2,121 residents per year (2022-2023). County health: 38% adult obesity, 16% smoke.

Population & Trend

Population shrank 8.7% from 612 (2022) to 559 (2024). Estimated 2026 population: ~511 (extrapolated at -4.3%/yr trend). Census Bureau Vintage estimate: 452.

Census data vintage2024
Population257,400 people
Annual growth rate · Population change-8.7%
Annual growth rate · Population (2022)612
Annual growth rate · Population (2024)559
Annual growth rate · Trend categoryshrinking
Population559 people
Population Estimate452

Sources: Census ACS 5-Year 2023, Table B01003  ·  Refreshed 2026-04-12

Age Distribution

Median age 43.3y is 4.4 years older than the U.S. median (38.9y). Children under 18 make up 17% — below the U.S. share of ~22%.

Age Summary · Median age43.3 years (vs Illinois 39.1y)
Age Summary · Children Pct17.0%
Age Summary · Characterestablished
Population under 1895
Median age43.3 years (vs Illinois 39.1y)

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Race, Ethnicity & Diversity

Of 559 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.05 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.

White residents592
Hispanic or Latino residents14
Diversity Index · Diversity index (Simpson)4.5%
Diversity Index · Diversity labelrelatively homogeneous
Diversity Index · Groups counted2
Diversity Index · Largest group share97.7%
Hispanic or Latino population1.3%
White (non-Hispanic) population95.5%

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Ancestry

Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.

Top (8)

(unnamed)
German
(unnamed)
Polish
(unnamed)
Irish
(unnamed)
American
(unnamed)
Hispanic Total
(unnamed)
Puerto Rican
(unnamed)
Italian
(unnamed)
English

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS). 0.4% are foreign-born — below the U.S. average of 13.9%. 0% have naturalized to U.S. citizenship.

Residents born in this state511
Residents born in another state43
Share born in this state91.4%
Share born in another state8.6%
Native-born U.S. citizens7.7%
Foreign-born residents0.4%
Naturalized citizens0.5%
Total foreign-born residents8,150

Households & Family Composition

255 households. Averaging 2.3 people each — smaller than the U.S. average of 2.5. 66% are family households — near the U.S. share of ~65%. Of 190 families, 32% are married couples with children.

Children under 18121
Total families190
Married couples with children61
Single-parent households9
Average household size2.27
Women who gave birth (past year)17.1%
Grandparents living with grandchildren5,013
Grandparents responsible for grandchildren1,639
Family households168 households
Households that are families65.9%
Total households255 households

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Residential Stability & Migration

How long residents have lived here and where they came from. 8.7% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 2,121 residents per year on net (IRS migration data).

Moved within the county (past year)8.7%
Migration · People moving in (annual)229,470
Migration · People moving out (annual)231,591
Migration · Net migration (in − out)-2,121
Migration · Year2022-2023

Sources: IRS SOI Migration 2021-2022  ·  Refreshed 2026-04-12

Disability

Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.

Residents with a disability50
Disability rate7.8%

Other

Congressional District · District12
Congressional District · FormattedIL-12
Congressional District · Congress118th
Cdc Birth Rate · Fips17,163
Cdc Birth Rate · State Fips17
Cdc Birth Rate · County Fips163
Cdc Birth Rate · CountySt Clair
Cdc Birth Rate · Birth Rate21.5%
Cdc Birth Rate · Lower Ci19.90
Cdc Birth Rate · Upper Ci23.20
Cdc Mortality · Fips17,163
Cdc Mortality · CountySt. Clair County
Cdc Mortality · Urban RuralLarge fringe metro
Cdc Mortality · Total Deaths 2020 20239,349
Cdc Vaccination · Fips17,163
Cdc Vaccination · CountySt. Clair County
Cdc Vaccination · Dose1 Pop Pct74.5%
Cdc Vaccination · Series Complete Pct65.8%
Cdc Vaccination · Booster Pct50.2%
Cdc Vaccination · Population 2019259,686
Cdc Vaccination · Metro StatusMetro
Family Score · Score10
Family Score · Schools20
Family Score · Children Pct17.0%
Family Score · Ratingexcellent
Town Summary · Key Factspopulation 559, shrinking, established, affluent, mixed
Town Summary · Population559 people
Town Summary · CountySt. Clair County

Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade