Henderson County area

Population and density of Henderson County

The Census Bureau estimates that 5,984 people lived in Henderson County on July 1, 2025. That ranks #2,809 of 3,222 county equivalents nationally and #92 of 102 in Illinois. Since the April 1, 2020 estimates base of 6,392, the population has declined by 408 (−6.4%), compared with −0.8% for Illinois as a whole.

With 378.8 square miles of land, that is 16 people per square mile (6.1 per km²), placing Henderson County #2,445 nationally for density and #99 in Illinois. The median county equivalent has 47 people per square mile; the Illinois median is 44. Put another way, there are about 41 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Henderson County

9 incorporated places lie at least partly in Henderson County. Together they are home to 3,102 people (51.8%); the other 2,882 (48.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Oquawka village, with 1,065 residents in the county. By land, Dallas City city is the largest at 2.374 mi² across all its counties.

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Henderson County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Henderson County is an outlying county of the Burlington, IA-IL Micropolitan Statistical Area. Its 2 county equivalents have 44,061 residents on 794.9 square miles of land; Henderson County accounts for 47.7% of the land and 13.6% of the residents. By combined land it ranks #267 of 542 micropolitan areas, and #284 by population. It belongs to the Burlington-Fort Madison, IA-IL Combined Statistical Area.

ZIP codes

17 ZIP Code Tabulation Areas have land in Henderson County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

6141861425614376144261447614506145361454614606146261469614716147561476614786148062330

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Henderson County

Henderson County shares a land border with 6 county equivalents, including 2 in Iowa. Each of them has more land than Henderson County. The largest neighbor is Hancock County (793.7 mi²) and the smallest is Des Moines County (416.1 mi²). Together with its neighbors, Henderson County forms a block of 3,799.1 mi² of land, of which it holds 10%.

How big is Henderson County compared with U.S. states?

Henderson County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.7 times as much. Illinois’s county land could hold about 147 areas the size of Henderson County.

Another way to picture it: the same land area would fill a square about 19.5 miles (31.3 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Henderson County?

Henderson County has more land than 614 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Henderson County at #2,623 nationally by total area, 15 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 4.2%, compared with a national county-equivalent median of 1.2% — 3 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Henderson County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.