When was Calhoun County founded?

Calhoun County was founded in 1825, formed from Pike County, and named after John C. Calhoun.

What is the county seat of Calhoun County?

The county seat of Calhoun County is Hardin.

Is there an online parcel map for Calhoun County?

Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.

Has Calhoun County's boundary or name changed?

Calhoun County was created in 1825 from Pike County. The Atlas of Historical County Boundaries records no boundary change since.

Is my lot in a flood zone?

We do not have flood maps for Calhoun County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 17013

Calhoun CountyIllinois

Calhoun County is a county in Illinois with its seat in Hardin. It was formed on January 10, 1825.

Founded1825
County seatHardin
Named forJohn C. Calhoun
Land area254 sq mi + 30 sq mi water
Population4,437 2020 Census

Open the free map Click any parcel in Calhoun County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 19 October 2026

Census outline · seat marked

History

Formed in 1825 from Pike County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Calhoun County was created from Pike County on January 10, 1825, and named after John C. Calhoun.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1825
Calhoun County created Calhoun created from Pike.
from Pike
10 January 1825 · Ill. Laws 1824-1825, pp. 65-67

Land and parcels

What the maps cover in Calhoun

Who publishes each layer, how good it is, and when we last checked.

Parcels Missing

No public parcel map found for Calhoun County yet. Lot lines and owners of record are kept by the county assessor's office.
Address points Missing

No public address points layer found for Calhoun County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Calhoun by the Census

Population

4,437 2020 Census count

Housing units

2,282 2020 Census count

Land area

254 square miles

Water area

30 square miles

People per sq mi

17 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

See your own lot on these maps

Open Calhoun County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Calhoun County

When was Calhoun County founded?: Calhoun County was founded in 1825, formed from Pike County, and named after John C. Calhoun.
What is the county seat of Calhoun County?: The county seat of Calhoun County is Hardin.
Is there an online parcel map for Calhoun County?: Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.
Has Calhoun County's boundary or name changed?: Calhoun County was created in 1825 from Pike County. The Atlas of Historical County Boundaries records no boundary change since.
Is my lot in a flood zone?: We do not have flood maps for Calhoun County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

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