St. Jacob: Demographics & People
St. Jacob is home to 1,759 people, in 567 households. Population grew 8.8% from 1,617 (2022) to 1,759 (2024). Median age 33.9 years. (6.3y younger than Madison County; 5.2y younger than Illinois). Children under 18 are 37% of the population. Population is 92% White (non-Hispanic) and 1% Hispanic or Latino. The community is relatively homogeneous (Simpson index 0.05). 82% of households are family-led. County is gaining 956 residents per year (2022-2023). County health: 36% adult obesity, 15% smoke.
- 3.1 people per household.
- 18% non-family households (singles, roommates).
Population & Trend
Population grew 8.8% from 1,617 (2022) to 1,759 (2024) — about 14.6× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~1,916 (extrapolated at 4.4%/yr trend). Census Bureau Vintage estimate: 2,140.
| Census data vintage | 2024 |
|---|---|
| Population | 265,859 people |
| Annual growth rate · Population change | 8.8% |
| Annual growth rate · Population (2022) | 1,617 |
| Annual growth rate · Population (2024) | 1,759 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | booming |
| Population | 1,759 people |
| Population Estimate | 2,140 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 33.9y is 5.0 years younger than the U.S. median (38.9y). Children under 18 make up 37% — above the U.S. share of ~22%.
| Age Summary · Median age | 33.9 years (vs Illinois 39.1y) |
|---|---|
| Age Summary · Children Pct | 37.0% |
| Age Summary · Character | young professional |
| Population under 18 | 650 |
| Median age | 33.9 years (vs Illinois 39.1y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 1,759 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 residents | 1,509 |
|---|---|
| Asian residents | 6 |
| Hispanic or Latino residents | 30 |
| Diversity Index · Diversity index (Simpson) | 4.6% |
| Diversity Index · Diversity label | relatively homogeneous |
| Diversity Index · Groups counted | 3 |
| Diversity Index · Largest group share | 97.7% |
| Hispanic or Latino population | 1.1% |
| White (non-Hispanic) population | 92.2% |
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)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS). 0.3% are foreign-born — below the U.S. average of 13.9%.
| Residents born in this state | 1,182 |
|---|---|
| Residents born in another state | 571 |
| Share born in this state | 67.2% |
| Share born in another state | 32.8% |
| Native-born U.S. citizens | 32.5% |
| Foreign-born residents | 0.3% |
| Total foreign-born residents | 2 |
| From Africa | 2 |
Households & Family Composition
567 households. Averaging 3.1 people each — larger than the U.S. average of 2.5. 82% are family households — above the U.S. share of ~65%. Of 415 families, 56% are married couples with children.
| Children under 18 | 576 |
|---|---|
| Total families | 415 |
| Married couples with children | 231 |
| Single-parent households | 23 |
| Average household size | 3.06 |
| Women who gave birth (past year) | 14.1% |
| Grandparents living with grandchildren | 6 |
| Grandparents responsible for grandchildren | 6 |
| Family households | 462 households |
| Households that are families | 81.5% |
| Total households | 567 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. 5.7% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 956 residents per year on net (IRS migration data).
| Moved within the county (past year) | 5.7% |
|---|---|
| Migration · People moving in (annual) | 237,226 |
| Migration · People moving out (annual) | 236,270 |
| Migration · Net migration (in − out) | 956 |
| Migration · Population growing | Yes |
| Migration · Year | 2022-2023 |
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 disability | 84 |
|---|---|
| Disability rate | 5.3% |
Other
| Congressional District · District | 15 |
|---|---|
| Congressional District · Formatted | IL-15 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 17,119 |
| Cdc Birth Rate · State Fips | 17 |
| Cdc Birth Rate · County Fips | 119 |
| Cdc Birth Rate · County | Madison |
| Cdc Birth Rate · Birth Rate | 17.0% |
| Cdc Birth Rate · Lower Ci | 15.60 |
| Cdc Birth Rate · Upper Ci | 18.60 |
| Cdc Mortality · Fips | 17,119 |
| Cdc Mortality · County | Madison County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 10,097 |
| Cdc Vaccination · Fips | 17,119 |
| Cdc Vaccination · County | Madison County |
| Cdc Vaccination · Dose1 Pop Pct | 71.4% |
| Cdc Vaccination · Series Complete Pct | 64.6% |
| Cdc Vaccination · Booster Pct | 53.6% |
| Cdc Vaccination · Population 2019 | 262,966 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 10 |
| Family Score · Schools | 20 |
| Family Score · Children Pct | 37.0% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 1,759, booming, young professional, affluent, white collar |
| Town Summary · Population | 1,759 people |
| Town Summary · County | Madison County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade