Rock Island County vs Sangamon County

A side-by-side comparison of Rock Island County and Sangamon County: population, income, housing, and more.

Rock Island County and Sangamon County are counties in Illinois. This page compares them across population, income, housing, education, commuting, and how each has changed since 2019.

Sangamon County has the higher population (195,217 vs 142,995 in Rock Island County). Sangamon County has the higher median household income ($74,114 vs $66,768 in Rock Island County). Sangamon County has the higher median home value ($170,300 vs $144,700 in Rock Island County).

Population, income & housing

	Rock Island County	Sangamon County
Population	142,995	195,217
Median age	40.3 yrs	40.8 yrs
Median household income	$66,768	$74,114
Median home value	$144,700	$170,300
Median gross rent	$863	$954
Housing units	66,742	93,151
Homeownership rate	68.6%	70.6%
Bachelor's degree or higher	24.1%	35.1%
Unemployment rate	5.7%	5.5%

Trends (ACS 5-year, 2019–2023)

	Rock Island County	Sangamon County
Population	143,873 → 142,995 (-0.6%)	196,861 → 195,217 (-0.8%)
Median household income	$54,858 → $66,768 (+21.7%)	$61,912 → $74,114 (+19.7%)
Median home value	$119,400 → $144,700 (+21.2%)	$141,200 → $170,300 (+20.6%)
Median gross rent	$748 → $863 (+15.4%)	$820 → $954 (+16.3%)

Rock Island County

Population

143,873142,995

Median household income

$54,858$66,768

Median home value

$119,400$144,700

Median gross rent

$748$863

Sangamon County

Population

196,861195,217

Median household income

$61,912$74,114

Median home value

$141,200$170,300

Median gross rent

$820$954

Age & race/ethnicity

Age distribution (share)

	Rock Island County	Sangamon County
Under 5	5.9%	5.6%
5 to 17	16.7%	16.4%
18 to 24	8.8%	7.9%
25 to 34	12.0%	12.2%
35 to 44	12.2%	12.9%
45 to 54	11.4%	12.2%
55 to 64	13.0%	13.9%
65 to 74	11.7%	11.4%
75 and over	8.4%	7.5%

Race & ethnicity (share)

	Rock Island County	Sangamon County
White (non-Hispanic)	68.5%	78.1%
Black or African American	10.4%	12.5%
American Indian & Alaska Native	0.1%	0.1%
Asian	2.5%	2.1%
Native Hawaiian & Pacific Islander	0.0%	0.0%
Some other race	0.2%	0.5%
Two or more races	4.2%	4.0%
Hispanic or Latino	14.0%	2.8%

Educational attainment (age 25+)

Share of adults 25+

	Rock Island County	Sangamon County
No high school diploma	9.8%	6.3%
High school graduate	30.7%	28.2%
Some college or associate's	35.5%	30.4%
Bachelor's degree	15.1%	20.9%
Graduate or professional degree	9.0%	14.2%

Commute to work

How workers get to work (share)

	Rock Island County	Sangamon County
Drove alone	79.1%	78.3%
Carpooled	8.3%	5.9%
Public transit	1.5%	1.1%
Walked	3.2%	1.3%
Bicycle	0.2%	0.4%
Worked from home	6.7%	12.0%
Other means	1.0%	0.9%

Housing

Units in structure (share)

	Rock Island County	Sangamon County
1-unit, detached	69.9%	72.7%
1-unit, attached	4.1%	5.3%
2 to 4 units	7.2%	5.9%
5 to 19 units	8.7%	7.5%
20 or more units	7.6%	4.5%
Mobile home & other	2.5%	4.1%

Poverty & households

	Rock Island County	Sangamon County
Poverty rate	15.4%	12.9%
Average household size	2.26	2.27
Mean commute (minutes)	20	20
Median year structure built	1962	1973