| ZIP Codes: | 17 ZIP Codes (15 Standard, 2 PO Box, 0 Unique) [See All] |
| Area Codes: | 217 / 447 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:11:58 PM |
| Population: | 64,474 [See All] |
| FIPS: | 17001 |
| CBSA: | Quincy, IL-MO |
| Land Area: | 835 sq mi |
| Water Area: | 10 sq mi |
| Coordinates: | 40.0141, -91.2061 |
| Quick Link: |
64,474 residents live across 17 ZIPs covering 835 sq mi, served by 15 distinct USPS-recognized cities.
Population moved from 66,977 to 64,474 from 2014 to 2024 — a -3.7% change. 7 ZIPs gained residents, 9 lost.
The county's wealthiest ZIP 62347 (Liberty, $93,810 median) and poorest ZIP 62301 (Quincy, $52,055) are 16.3 miles apart — a 1.8× income gap across local geography.
Median home values vary 2.6× across this county — from $87,700 in 62349 (Loraine) to $226,800 in 62338 (Fowler).
Density varies 234× across the county — from 11 people/sq mi in 62349 (Loraine) to 2,547 in 62301 (Quincy).
Educational attainment ranges from 13.4% bachelor's+ in 62349 (Loraine) to 35.0% in 62305 (Quincy) — the breadth of educational profiles across the area.
Within Illinois, this is the #22 most populous of 102 counties and ranks #51 for median household income .
Weighted by population, the typical household earns about $66,587 across the county — reflecting what a typical resident sees, not a simple ZIP average.
27.6% of adults age 25+ hold a bachelor's degree or higher (12,365 of 44,837 reporting).
15 Standard delivery, 2 PO Box only, 0 single-entity Unique ZIPs serve this county.
A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 62301 | Quincy | Standard | 30,746 | $52,055 | 12.1 | -6.9% |
| 62305 | Quincy | Standard | 19,036 | $83,598 | 148.1 | 1.0% |
| 62320 | Camp Point | Standard | 2,667 | $77,143 | 83.2 | 29.6% |
| 62347 | Liberty | Standard | 1,977 | $93,810 | 117.2 | -19.5% |
| 62351 | Mendon | Standard | 1,928 | $77,298 | 74.5 | -0.3% |
| 62360 | Payson | Standard | 1,605 | $54,706 | 38.6 | -20.3% |
| 62376 | Ursa | Standard | 1,276 | $57,778 | 69.8 | 14.3% |
| 62324 | Clayton | Standard | 1,196 | $76,903 | 94.6 | 7.9% |
| 62338 | Fowler | Standard | 1,075 | $91,473 | 34.9 | -5.2% |
| 62339 | Golden | Standard | 970 | $62,422 | 26.9 | -2.6% |
| 62349 | Loraine | Standard | 517 | $67,981 | 47.4 | 8.8% |
| 62325 | Coatsburg | Standard | 465 | $75,469 | 18.0 | 14.3% |
| 62365 | Plainville | Standard | 464 | $90,833 | 25.8 | -41.8% |
| 62348 | Lima | PO Box | 204 | $77,969 | 0.0 | 25.9% |
| 62359 | Paloma | Standard | 184 | $51,413 | 3.2 | -29.2% |
| 62346 | La Prairie | Standard | 164 | — | 40.6 | -10.9% |
| 62306 | Quincy | PO Box | — | — | 0.0 | — |