Hamilton County is a county in Illinois, United States, in the region locally called “Little Egypt.” It had a population of 7,993 at the 2020 census and covers 436 square miles (1,130 km2) centred near 38°05′N 88°32′W.
McLeansboro is the county seat, and its postal code is 62859. The county has 1 city, 1 incorporated town, 3 villages and a wider list of unincorporated communities, grouped into 12 civil townships. Hamilton County sits in the Central time zone.
Towns & Villages in Hamilton County
Hamilton County has five incorporated places — one city, one town and three villages — and a long list of smaller unincorporated communities, several no more than a crossroads store or a rural post office name. In the table below, “City · seat” marks McLeansboro, “Town” marks Belle Prairie City, and “Unincorp.” covers every place with no municipal government of its own.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| McLeansboro | City · seat | McLeansboro | — | 62859 |
| Belle Prairie City | Town | — | — | — |
| Broughton | Village | — | — | 62817 |
| Dahlgren | Village | Dahlgren | — | 62828 |
| Macedonia | Village | — | — | 62860 |
| Aden | Unincorp. | — | — | — |
| Blairsville | Unincorp. | Flannigan | — | — |
| Braden | Unincorp. | — | — | — |
| Bungay | Unincorp. | — | — | — |
| Cornerville | Unincorp. | — | — | — |
| Dale | Unincorp. | — | — | 62829 |
| Delafield | Unincorp. | — | — | — |
| Diamond City | Unincorp. | — | — | — |
| Flint | Unincorp. | — | — | — |
| Garrison | Unincorp. | — | — | — |
| Hoodville | Unincorp. | — | — | — |
| Lovilla | Unincorp. | — | — | — |
| Nipper Corner | Unincorp. | — | — | — |
| Olga | Unincorp. | — | — | — |
| Piopolis | Unincorp. | — | — | — |
| Rural Hill | Unincorp. | — | — | — |
| Thackeray | Unincorp. | — | — | — |
| Thurber | Unincorp. | — | — | — |
| Tuckers Corners | Unincorp. | — | — | — |
| University | Unincorp. | — | — | — |
| Walpole | Unincorp. | — | — | — |
| West Rural Hill | Unincorp. | — | — | — |
Rural Hill and West Rural Hill are two separate, adjacent named places on county maps, not a duplicate listing. Diamond City and Piopolis lie close together northeast of McLeansboro and are sometimes confused for one settlement, but both carry distinct names on record.
Townships
Hamilton County is organized into 12 civil townships: Beaver Creek, Crook, Crouch, Dahlgren, Flannigan, Knight Prairie, Mayberry, McLeansboro, South Crouch, South Flannigan, South Twigg and Twigg. Per-township 2020 population figures were not verified and are omitted below rather than estimated.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| McLeansboro | — | McLeansboro |
| Dahlgren | — | Dahlgren |
| Flannigan | — | Blairsville |
| Beaver Creek | — | — |
| Crook | — | — |
| Crouch | — | — |
| Knight Prairie | — | — |
| Mayberry | — | — |
| South Crouch | — | — |
| South Flannigan | — | — |
| South Twigg | — | — |
| Twigg | — | — |
ZIP Codes
- 62859 — McLeansboro (also serves Belle Prairie City and Aden)
- 62828 — Dahlgren
- 62817 — Broughton
- 62860 — Macedonia
- 62829 — Dale (PO Box delivery only)
Smaller unincorporated communities such as Blairsville, Braden and Piopolis have no ZIP code of their own and are served by the nearest post office town listed above.
Geography
Hamilton County lies in the hilly southern part of Illinois, in the region known locally as Little Egypt, with rolling, partly wooded terrain draining toward the Wabash and Saline watersheds. The county covers 436 square miles, of which about 1.2 square miles is water. Illinois Routes 14, 142 and 242 cross the county.
Hamilton County borders Wayne County to the north, White County to the east, Gallatin County to the southeast, Saline County to the south, Franklin County to the west and Jefferson County to the northwest. See Wayne County, White County, Gallatin County, Saline County, Franklin County and Jefferson County.
Demographics
Hamilton County had 7,993 residents at the 2020 census. McLeansboro is by far the largest community, followed by Dahlgren. County-level median household income was not verified against a cited source; the Illinois median stands at $80,306, and rural downstate counties like Hamilton typically run well below the state figure. Population density works out to roughly 18 people per square mile, among the more sparsely settled counties in southern Illinois.
Economy & Local Life
Agriculture — row crops and livestock on the county’s rolling farmland — anchors the local economy, alongside county government, schools and small retail centred on McLeansboro’s courthouse square. Hamilton County High School serves the county’s students.
History
Hamilton County was organized in 1821, carved out of White County, and named for Alexander Hamilton, the first U.S. Treasury Secretary. On March 18, 1925, the county was struck by the Tri-State Tornado, the deadliest tornado in U.S. history, which killed 41 people in the county as it cut across southern Illinois into Indiana.
Getting There
Illinois Route 14 runs east–west through McLeansboro, meeting Route 142 and Route 242 within the county.
- Mount Vernon — 20 miles northwest
- Harrisburg — 25 miles southeast
- Carmi — 20 miles east
- Mount Carmel — 40 miles northeast
The nearest commercial airport is Southern Illinois Airport in Murphysboro, roughly an hour’s drive southwest.
Frequently Asked Questions
Where is Hamilton County, Illinois?
It is in the southeastern part of the state, in the Little Egypt region, between Mount Vernon and Harrisburg.
What is the population of Hamilton County?
7,993 people, at the 2020 census.
How big is Hamilton County?
436 square miles (1,130 km2), of which about 435 square miles is land.
What is the county seat of Hamilton County?
McLeansboro is the county seat and largest community.
How many towns are in Hamilton County?
One city, one incorporated town, three villages, and a long list of smaller unincorporated communities.
What ZIP codes are in Hamilton County?
62859 (McLeansboro), 62828 (Dahlgren), 62817 (Broughton), 62860 (Macedonia) and 62829 (Dale).
What happened in Hamilton County in 1925?
The Tri-State Tornado struck the county on March 18, 1925, killing 41 people — part of the deadliest tornado track in U.S. history.
More counties in this state: Towns and villages in Illinois.