Marshall County, Illinois
County seat: Lacon · Population 11,473 (2025) · 387 sq mi
Marshall County is the 84th most populous of Illinois's 102 counties, with 11,473 people (2025 estimate). Its county seat is Lacon. It is part of the North Central region, one of the 10 Illinois economic development regions (DCEO). The map shows its 9 cities and towns and the 6 neighboring counties.
Marshall County facts
- County seat
- Lacon
- Population (2025 estimate)
- 11,473 −2.4% since 2020
- Land area
- 387 sq mi 74th largest of 102
- Water area
- 12 sq mi
- Population density
- 30 per sq mi
- Established
- 1839
- Same name
- One of 12 Marshall Counties in the US
- Named after
- John Marshall chief justice of the United States from 1801 to 1835, (1755-1835)
- Largest city
- Henry 2,280
- Median household income
- $71,585
- Cities and towns
- 9
- ZIP codes
- 19
- Time zone
- Central
- FIPS code
- 17123
Cities and towns in Marshall County
Marshall County has 9 incorporated cities, towns and villages. Populations count the people living inside Marshall County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Henry | City | 2,280 | |
| Lacon (county seat) | City | 1,822 | |
| Toluca | City | 1,310 | |
| Wenona | City | 935 | LaSalle County |
| Hopewell | Village | 411 | |
| Varna | Village | 365 | |
| Sparland | Village | 353 | |
| La Rose | Village | 103 | |
| Washburn | Village | 56 | Woodford County |
ZIP codes in Marshall County
19 ZIP codes reach into Marshall County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 61321 also LaSalle County
- 61336 also Putnam County
- 61358 also LaSalle County
- 61369
- 61375
- 61377 also LaSalle County
- 61421 also Stark and Bureau counties
- 61424
- 61479 also Stark County
- 61491 also Stark County
- 61523 also Peoria County
- 61526 also Peoria County
- 61537 also Bureau County
- 61540
- 61541
- 61560 also Putnam and Bureau counties
- 61565 also Peoria County
- 61570 also Woodford County
- 61760 also Woodford County
Population of Marshall County, 2020–2025
Marshall County shrank by 277 people (−2.4%) between April 2020 and July 2025: 347 more deaths than births and a net gain of 74 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 11,713 |
| 2021 | 11,668 |
| 2022 | 11,658 |
| 2023 | 11,663 |
| 2024 | 11,571 |
| 2025 | 11,473 |
Neighboring counties
- Woodford County south · 38,111 people
- Putnam County north · 5,619 people
- LaSalle County northeast · 107,773 people
- Peoria County southwest · 178,553 people
- Stark County west · 5,319 people
- Bureau County north · 32,510 people
Printable Marshall County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (83 KB)
- PNG (2400 px) (56 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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