• county
  • FIPS 17001
  • Largest town: Quincy

Adams County, Illinois

Adams County had 64,109 residents in the Census Vintage 2024 estimate, on 855.2 square miles of land. It ranks 23rd of 102 in Illinois by population and 12th by land area.

Population
64,109
#23 of 102 in Illinois · #852 in US
Area
855.2 sq mi
#12 of 102 in Illinois · #975 in US
Density
75 / sq mi
#32 of 102 in Illinois · #1,130 in US
Median household income
$63,424
#65 of 102 in Illinois · #1,521 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Adams County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Adams County

Adams County population, land area and income

Adams County had 64,109 residents in the Census Vintage 2024 estimate, on 855.2 square miles of land. It ranks 23rd of 102 in Illinois by population and 12th by land area. That works out to 75.0 people per square mile, below the US average of 96.3, and above the national county median.

The median county-equivalent in Illinois has 24,447 residents, so Adams County is 2.6 times that size.

Its SAIPE 2023 median household income of $63,424 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

64,109

3144th1st

852nd of 3,144 (US)

Land area

855 sq mi

3144th1st

975th of 3,144 (US)

Density

75.0 / sq mi

3144th1st

1130th of 3,144 (US)

Median household income

$63,424

3143rd1st

1521st of 3,143 (US)

Rank within Illinois (102)

Population

64,109

102nd1st

23rd of 102 (IL)

Land area

855 sq mi

102nd1st

12th of 102 (IL)

Density

75.0 / sq mi

102nd1st

32nd of 102 (IL)

Median household income

$63,424

102nd1st

65th of 102 (IL)

How Adams County's population changed since 2020

Adams County lost 1,513 residents between the July 2020 and July 2024 estimates, a drop of 2.3%. That ranks 68th of 102 in Illinois for growth. The median Illinois county changed by -1.7%, and the state as a whole by -0.7%.

Since the April 2020 estimates base, Adams County recorded 2,942 births and 3,624 deaths, a natural change of -682. Net international migration added +108 and net domestic migration, people moving to or from other US counties, came to -1,054. The largest single component was domestic migration, which removed 1,054 people.

65.6k202065.1k202164.5k202264.4k202364.1k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
2,942
Deaths
3,624
Net international migration
+108
Net domestic migration
-1,054
Change, July 2023 to July 2024
-326

Where Adams County is

The Census internal point of Adams County is at 39.986100, -91.195000. It sits in UTM zone 15N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Adams County outlined. Dots are towns of 1,000+ people with residents in it.

Piatt County: -0.3%Hamilton County: -2.2%Williamson County: -0.1%Edgar County: -2.4%Macoupin County: -2.3%Marshall County: -1.3%Putnam County: +0.0%Richland County: -2.8%Washington County: -1.4%Lee County: -1.5%Douglas County: +0.2%Cook County: -1.6%Effingham County: -0.3%Edwards County: -3.6%Cass County: -2.0%Clay County: -3.4%Knox County: -2.2%LaSalle County: -0.9%Cumberland County: -1.3%Warren County: -3.7%Moultrie County: -0.9%Menard County: -2.5%Fayette County: -1.5%Boone County: -0.0%Lawrence County: -3.2%Marion County: -3.2%Champaign County: +3.0%Clark County: -2.4%Ford County: -0.4%Wayne County: -1.4%Logan County: -1.4%Grundy County: +2.5%Jasper County: -1.8%Crawford County: -1.3%McDonough County: -1.7%Clinton County: +0.5%Perry County: -3.0%Montgomery County: -2.2%Henry County: -2.0%Livingston County: -1.2%Scott County: -3.8%Alexander County: -11.2%Bureau County: -2.2%Brown County: +1.1%Mason County: -3.9%Calhoun County: -4.1%Greene County: -4.3%Coles County: -1.4%Kendall County: +8.2%Lake County: +0.7%Mercer County: -2.2%St. Clair County: -2.3%Wabash County: -3.0%Bond County: -1.7%DuPage County: +0.6%Gallatin County: -5.2%Stephenson County: -3.3%McHenry County: +1.9%White County: -3.0%Saline County: -3.9%Christian County: -2.2%Sangamon County: -1.0%Massac County: -3.6%Macon County: -2.9%Johnson County: -0.0%Jo Daviess County: -2.6%Peoria County: -1.0%DeKalb County: +1.0%Pope County: -1.5%De Witt County: -0.9%Schuyler County: -1.7%Fulton County: -3.1%Ogle County: -0.8%Jersey County: -1.6%Iroquois County: -3.3%Kankakee County: -0.9%Rock Island County: -1.1%Pulaski County: -5.8%Kane County: +0.9%Union County: -2.4%Whiteside County: -1.7%Woodford County: -0.3%Carroll County: -1.5%Adams County: -2.3%Hardin County: -2.6%Madison County: -1.0%Hancock County: -3.1%Monroe County: +0.0%Tazewell County: -1.1%Jackson County: -0.1%Vermilion County: -3.9%Randolph County: -0.6%McLean County: +0.5%Morgan County: -2.6%Shelby County: -1.7%Will County: +1.7%Winnebago County: -0.4%Jefferson County: -2.4%Stark County: -2.2%Henderson County: -4.5%Pike County: -2.6%Franklin County: -1.8%
Change 2020 to 2024
  1. < -3.0%
  2. < -2.2%
  3. < -1.4%
  4. < -0.3%
  5. ≥ -0.3%
no data

Orange pin: Adams County internal point. Dark pin: Springfield.

Internal point

Decimal
39.986100, -91.195000
DMS
39°59'9.96"N 91°11'42.00"W
UTM
15N 654110.0E 4427774.6N
Geohash
9zp5kz1zf
Plus code
86FCXRP4+C2

Towns in Adams County

2 incorporated places of 1,000+ people have residents in Adams County, 39,903 people together, or 62% of the county. Each figure counts only the part of the town inside Adams County; towns marked "part" extend into another county. The largest is Quincy with 38,786.

  1. 01Quincy38,786
  2. 02Camp Point1,117
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Adams County

The Census 2024 county adjacency file lists 6 neighbors for Adams County, including 2 across a state line. The most populous is Marion County, MO, with 28,425 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 83.1 miles E of Adams County's internal point in a straight line. The nearest place of 100,000 or more is Springfield, IL (population 112,949), 83.3 miles away. The nearest place of 10,000 or more is Quincy, IL (population 38,786), 10.4 miles away.

Adams County FIPS code

The FIPS code of Adams County is 17001: state code 17 for Illinois plus county code 001. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $63,424.

Questions people ask

What is the population of Adams County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 64,109. That is down 1,513 people (2.3%) from the July 2020 estimate of 65,622.

What is the FIPS code of Adams County?

17001. The first two digits (17) are Illinois; the last three (001) identify the county.

What is the largest town in Adams County?

Quincy, with 38,786 residents inside Adams County in 2024.

Which counties border Adams County?

6 county-equivalents border it in the Census 2024 adjacency file: Marion County, MO; Hancock County, IL; Pike County, IL; Lewis County, MO; Schuyler County, IL; Brown County, IL.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.