St. Joseph: Demographics & People
Census counts 71,236 people in St. Joseph, in 28,756 households. Population shrank 0.4% from 71,542 (2022) to 71,236 (2024). Median age 38.1 years. (0.8y younger than Buchanan County; 1.1y younger than Missouri). Children under 18 are 22% of the population. Population is 77% White (non-Hispanic) and 8% Hispanic or Latino. The community is somewhat diverse (Simpson index 0.29). 56% of households are family-led. County is losing 125 residents per year (2022-2023). County health: 40% adult obesity, 20% smoke.
- 2.5 people per household.
- 44% non-family households (singles, roommates).
Population & Trend
Population shrank 0.4% from 71,542 (2022) to 71,236 (2024). Estimated 2026 population: ~70,930 (extrapolated at -0.2%/yr trend). Census Bureau Vintage estimate: 70,521.
| Census data vintage | 2024 |
|---|---|
| Population | 84,793 people |
| Annual growth rate · Population change | -0.4% |
| Annual growth rate · Population (2022) | 71,542 |
| Annual growth rate · Population (2024) | 71,236 |
| Annual growth rate · Trend category | stable |
| Population | 71,236 people |
| Population Estimate | 70,521 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 38.1y is 0.8 years younger than the U.S. median (38.9y). Children under 18 make up 22% — near the U.S. share of ~22%.
| Age Summary · Median age | 38.1 years (vs Missouri 39.2y) |
|---|---|
| Age Summary · Children Pct | 22.1% |
| Age Summary · Character | family-oriented |
| Population under 18 | 15,748 |
| Median age | 38.1 years (vs Missouri 39.2y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 71,236 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.29 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.
| White residents | 57,529 |
|---|---|
| Black residents | 4,775 |
| Asian residents | 970 |
| Hispanic or Latino residents | 5,494 |
| Diversity Index · Diversity index (Simpson) | 28.9% |
| Diversity Index · Diversity label | somewhat diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 83.7% |
| Asian population | 1.2% |
| Black population | 6.5% |
| Hispanic or Latino population | 8.4% |
| White (non-Hispanic) population | 77.3% |
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). 0.9% are foreign-born — below the U.S. average of 13.9%. 4% have naturalized to U.S. citizenship.
| Residents born in this state | 50,583 |
|---|---|
| Residents born in another state | 16,787 |
| Share born in this state | 71.0% |
| Share born in another state | 29.0% |
| Native-born U.S. citizens | 23.6% |
| Foreign-born residents | 0.9% |
| Naturalized citizens | 4.5% |
| Total foreign-born residents | 3,158 |
| From Europe | 66 |
| From Africa | 937 |
| Census Foreign Born · Caribbean | 85 |
Households & Family Composition
28,756 households. Averaging 2.4 people each — smaller than the U.S. average of 2.5. 56% are family households — below the U.S. share of ~65%. Of 16,231 families, 23% are married couples with children.
| Children under 18 | 15,909 |
|---|---|
| Total families | 16,231 |
| Married couples with children | 3,684 |
| Single-parent households | 954 |
| Average household size | 2.38 |
| Women who gave birth (past year) | 20.2% |
| Grandparents living with grandchildren | 1,269 |
| Grandparents responsible for grandchildren | 332 |
| Family households | 15,960 households |
| Households that are families | 55.5% |
| Total households | 28,756 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. 14.8% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 125 residents per year on net (IRS migration data).
| Moved within the county (past year) | 14.8% |
|---|---|
| Migration · People moving in (annual) | 72,762 |
| Migration · People moving out (annual) | 72,887 |
| Migration · Net migration (in − out) | -125 |
| 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 | 5,934 |
|---|---|
| Disability rate | 8.5% |
Group Quarters
Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 3,251 residents live in group quarters (4.6% of population).
| Living in group quarters | 3,251 |
|---|
Other
| Congressional District · District | 6 |
|---|---|
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 29,021 |
| Cdc Birth Rate · State Fips | 29 |
| Cdc Birth Rate · County Fips | 21 |
| Cdc Birth Rate · County | Buchanan |
| Cdc Birth Rate · Birth Rate | 30.6% |
| Cdc Birth Rate · Lower Ci | 27.40 |
| Cdc Birth Rate · Upper Ci | 34.00 |
| Cdc Mortality · Fips | 29,021 |
| Cdc Mortality · County | Buchanan County |
| Cdc Mortality · Urban Rural | Small metro |
| Cdc Mortality · Total Deaths 2020 2023 | 4,460 |
| Cdc Vaccination · Fips | 29,021 |
| Cdc Vaccination · County | Buchanan County |
| Cdc Vaccination · Dose1 Pop Pct | 46.7% |
| Cdc Vaccination · Series Complete Pct | 40.6% |
| Cdc Vaccination · Booster Pct | 45.7% |
| Cdc Vaccination · Population 2019 | 87,364 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 2.00 |
| Family Score · Schools | 2 |
| Family Score · Children Pct | 22.1% |
| Family Score · Rating | limited |
| Town Summary · Key Facts | population 71,236, stable, family-oriented, middle-class, mixed |
| Town Summary · Population | 71,236 people |
| Town Summary · County | Buchanan County |
Sources: NCES school congressional district assignment · federal dataset cascade