Hancock County is a county in Illinois, United States, on the Mississippi River across from Iowa and Missouri, in the west-central part of the state. It had a population of 17,620 people at the 2020 census and covers 814 square miles (2,110 km2), of which 794 square miles (2,060 km2) is land, centred near 40°24′N 91°10′W.
Carthage is the county seat, and its postal code is 62321. The county has 6 cities, 8 villages, 1 town, 1 census-designated place and about 20 unincorporated communities spread across 24 civil townships. It sits in the Central time zone.
Towns & Villages in Hancock County
Hancock County’s 35 named places range from the river cities of Hamilton and Warsaw to farm hamlets that never grew past a church and a grain elevator. “City” and “Village” are incorporated municipalities under Illinois law; “CDP” is an unincorporated Census-designated place; “Unincorp.” covers the rest. Population figures are not individually confirmed for this page and are marked —.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Adrian | Unincorp. | — | — | — |
| Augusta | Village | Augusta | — | 62311 |
| Basco | Village | — | — | 62313 |
| Bentley | Town | — | — | — |
| Bowen | Village | — | — | 62316 |
| Breckenridge | Unincorp. | — | — | — |
| Burnside | Unincorp. | — | — | — |
| Carthage | City · seat | Carthage | — | 62321 |
| Chili | Unincorp. | Chili | — | — |
| Colusa | Unincorp. | — | — | 62329 |
| Dallas City | City | Dallas City | — | 62330 |
| Denver | Unincorp. | — | — | — |
| Disco | Unincorp. | — | — | — |
| Durham | Unincorp. | Durham | — | — |
| Elderville | Unincorp. | — | — | — |
| Elvaston | Village | — | — | 62334 |
| Ferris | Village | — | — | 62336 |
| Fountain Green | Unincorp. | Fountain Green | — | — |
| Hamilton | City | — | — | 62341 |
| Joetta | Unincorp. | — | — | — |
| La Crosse | Unincorp. | — | — | — |
| La Harpe | City | La Harpe | — | 61450 |
| McCall | Unincorp. | — | — | — |
| Middle Creek | Unincorp. | — | — | — |
| Nauvoo | City | Nauvoo | — | 62354 |
| Niota | CDP | — | — | 62358 |
| Old Niota | Unincorp. | — | — | — |
| Plymouth | Village | — | — | — |
| Pontoosuc | Village | Pontoosuc | — | — |
| Powellton | Unincorp. | — | — | — |
| Saint Mary | Unincorp. | St. Mary | — | — |
| Stillwell | Unincorp. | — | — | — |
| Sutter | Unincorp. | — | — | 62373 |
| Tioga | Unincorp. | — | — | — |
| Warsaw | City | Warsaw | — | 62379 |
| Webster | Unincorp. | — | — | — |
| West Point | Village | — | — | 62380 |
Niota and Old Niota are two separate places on the river bluff a few miles apart — Niota is the Census-designated place, Old Niota an older unincorporated settlement upstream of it. Dallas City straddles the Hancock–Henderson county line, though the bulk of the city and its ZIP code sit in Hancock County.
Townships
Hancock County is divided into 24 civil townships. Individual 2020 township population figures are not confirmed for this page and are marked —; townships are listed alphabetically.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Appanoose | — | — |
| Augusta | — | Augusta |
| Bear Creek | — | — |
| Carthage | — | Carthage |
| Chili | — | Chili |
| Dallas City | — | Dallas City |
| Durham | — | Durham |
| Fountain Green | — | Fountain Green |
| Hancock | — | — |
| Harmony | — | — |
| La Harpe | — | La Harpe |
| Montebello | — | — |
| Nauvoo | — | Nauvoo |
| Pilot Grove | — | — |
| Pontoosuc | — | Pontoosuc |
| Prairie | — | — |
| Rock Creek | — | — |
| Rocky Run–Wilcox | — | — |
| St. Albans | — | — |
| St. Mary | — | Saint Mary |
| Sonora | — | — |
| Walker | — | — |
| Warsaw | — | Warsaw |
| Wythe | — | — |
ZIP Codes
- 62321 — Carthage (county seat)
- 62341 — Hamilton
- 62379 — Warsaw
- 61450 — La Harpe
- 62330 — Dallas City
- 62354 — Nauvoo
- 62311 — Augusta
- 62316 — Bowen
- 62358 — Niota
- 62313 — Basco
- 62380 — West Point
- 62373 — Sutter
- 62334 — Elvaston
- 62336 — Ferris
- 62329 — Colusa
Smaller places without their own post office, including Bentley, Plymouth and Pontoosuc, are served by the ZIP code of the nearest town listed above.
Geography
Hancock County sits on the east bank of the Mississippi River, which forms its entire western border with Lee County, Iowa, and Lewis and Clark counties in Missouri. Away from the river bluffs the land opens into rolling corn and soybean farmland typical of west-central Illinois, drained toward the Mississippi by Crooked Creek and Bear Creek.
The county borders Henderson County to the north, McDonough County to the east, Schuyler County and Adams County to the south, and across the Mississippi River, Lee County, Iowa to the northwest and Lewis County and Clark County, Missouri, to the southwest.
Demographics
Hancock County had 17,620 residents at the 2020 census, working out to about 22 people per square mile of land. Hamilton is the largest community, followed by Carthage, the county seat. Illinois’s median household income is $80,306; Hancock County, a rural farm county well below the state’s metro-heavy average, runs substantially lower than that figure.
Economy & Local Life
Grain and livestock farming anchor the county’s economy — corn and soybeans dominate the land, with hog and cattle operations common on family farms. Carthage, the seat, hosts the county courthouse and county government offices. Nauvoo, once a major 1840s Mormon settlement, now draws visitors for its restored historic district, the Nauvoo Illinois Temple, and the annual Nauvoo Grape Festival, tied to the town’s long history of winemaking.
History
Hancock County was organized on January 13, 1825, carved out of Pike County, and named for John Hancock, signer of the Declaration of Independence. In the 1840s Nauvoo became one of the largest cities in Illinois as thousands of Latter-day Saints settled there under Joseph Smith. Smith and his brother Hyrum were killed by a mob at the county jail in Carthage on June 27, 1844, and most of the Mormon population left the county for Utah within two years. The county’s third courthouse, on the Carthage square, was dedicated in 1908; an earlier 1839 courthouse on the same site hosted a joint appearance by Abraham Lincoln and Stephen Douglas during their 1858 Senate campaign.
Getting There
US Route 136 crosses the county east–west and Illinois Routes 9, 61, 94, 96 and 336 connect its towns; the Keokuk-Hamilton bridge and other Mississippi River crossings link the county directly to Iowa and Missouri.
- Keokuk, Iowa — about 1 mile west of Hamilton, across the Mississippi River
- Quincy, Illinois — about 30 miles south
- Macomb, Illinois — about 25 miles east
- Burlington, Iowa — about 30 miles north
The nearest commercial airport is Quincy Regional Airport (UIN) in Quincy, roughly 30 miles south.
Frequently Asked Questions
Where is Hancock County, Illinois?
It is in west-central Illinois, on the east bank of the Mississippi River across from Iowa and Missouri.
What is the population of Hancock County?
17,620 people, per the 2020 census.
How big is Hancock County?
814 square miles (2,110 km2) total, of which 794 square miles (2,060 km2) is land.
What is the county seat of Hancock County?
Carthage is the county seat.
How many towns and villages are in Hancock County?
The county has 6 cities, 8 villages, 1 town, 1 census-designated place and roughly 20 unincorporated communities across its 24 townships.
What ZIP codes are in Hancock County?
15 ZIP codes serve the county, including 62321 (Carthage), 62341 (Hamilton) and 62379 (Warsaw).
Why is Nauvoo historically significant?
It was a major Latter-day Saint settlement in the 1840s and is today home to the Nauvoo Illinois Temple and a restored historic district.
More counties in this state: Towns and villages in Illinois.