Adams County GIS Maps
Adams County, Illinois, has 65,737 residents and covers 855.1 square miles. The population declined 2% between the 2010 and 2020 census. More residents left than arrived over that decade. The FIPS code for Adams County is 17001.
Quincy is the county's largest population center. Adams County also includes 16 zip codes, 6 public school districts and 41 municipalities. Those boundaries help explain why population, schools, and housing can look different from one part of the county to another. The map below shows how those county lines, zip codes, and school districts fit together, and the sections that follow use that same geography to show population, demographics, school enrollment and housing patterns in more detail.
Maps, GIS layers and sample data. Paid packages add full layers, analytics and database files.
Adams County Trends
- Population
- 65,737▾
- Median Home Value
- $155,900▴
- K-12 Enrollment
- 9,146▾
County analytics dashboards with historical trends & projections included in package downloads.
Free starter access previews county maps, lightweight GIS, and sample data. Paid packages unlock full GIS layers, analytics, and database files.
Adams County Maps
The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.
County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.
Adams County Population
Adams County had 65,737 residents in 2020. That was 2% lower than in 2010. Adams County had 2,540 fewer people in 2020 than it did in 2000, which points to a long-term population decline. The county is fairly spread out, with about 77 people per square mile. Some of the county's most populated postal areas include Quincy, Quincy and Liberty.
Population Trend in Adams County IL
Adams County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.
Adams County Zip Codes
Adams County has 16 zip codes. Some of the county's most populated zip codes include Quincy (62301), Quincy (62305) and Liberty (62347). Quincy is the largest zip by population, with about 31,481 residents or 48% of the county total. Together, the three largest zips account for about 80% of all county residents based on 2020 population estimates.
Most Populated Zip Codes in Adams County IL
| ZIP | Area | Population | Trend |
|---|---|---|---|
| 62301 | Quincy | 31,481 | ▾ -6.7% |
| 62305 | Quincy | 19,042 | ▴ 5.5% |
| 62347 | Liberty | 2,371 | ▴ 3.9% |
| 62320 | Camp Point | 2,286 | ▴ 4.6% |
| 62351 | Mendon | 1,793 | ▾ -3.4% |
| Download all zip code data | |||
Adams County Zip Code populations and trends per most recent census data.
Adams County Demographics
Adams County has a median age of 41.1, which makes the county a little older than Illinois overall. About 22.7% of residents are under 18, while 20.1% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 29.1% of the population, which points to a solid working-age base. About 27% of adults have a bachelor's degree or higher, above the statewide figure of 37.2%. The county is mostly White by population, though Hispanic, Asian, Black and multiracial residents are also part of the local mix.
Key Demographics for Adams County IL
Median Age
41.1
Under 18
22.7%
Age 65+
20.1%
Bachelor's+
27%
Adams County School Districts
Adams County is served by 6 public school districts with 9,146 students enrolled in 2024. The largest districts on the county map are Quincy 172, Central CUSD 3 and Community Unit 4. Those three districts account for about 84% of public school enrollment in the map area. Total enrollment has stayed fairly steady in recent years, but it is slightly lower than it was in 2017.
Largest School Districts by Enrollment in Adams County IL
| District | Enrollment | Share | Trend |
|---|---|---|---|
| Quincy School District 172 | 6,264 | 68.5% | ▾ -0.2% |
| Central CUSD 3 | 743 | 8.1% | ▴ 1.6% |
| Community Unit School District 4 | 672 | 7.3% | ▴ 0.4% |
| Liberty Community Unit School District 2 | 589 | 6.4% | ▾ -5.6% |
| Payson Community Unit School District 1 | 449 | 4.9% | ▾ -6.3% |
| Download all school district data | |||
Adams County school district enrollment and trends per most recent NCES reporting data.
Adams County Housing & Real Estate
Adams County has a median home value of $155,900 and a median gross rent of $826. About 72% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run below the Illinois median, while rents come in below the state average. In March 2026, the median listing price was $216,625 and homes spent about 47 days on the market.
Adams County Housing Mix
Adams County housing mix: owner, renter and vacant units.
Adams County Housing Trends
Adams County median home value and rent trend (last 5 years).
Businesses in Adams County, IL
Adams County has 2,987 business listings across 570 categories. The largest categories in Adams County business listings are Churches & Religious Organizations (81, 2.7%), Insurance Agencies (51, 1.7%), and Community & Nonprofits (46, 1.5%). The full Adams County business listings dataset includes names, categories, addresses and contact details where available. Adams County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.
Top Business Categories in Adams County, IL
| Category | Businesses | Share |
|---|---|---|
| Churches & Religious Organizations | 81 | 2.7% |
| Insurance Agencies | 51 | 1.7% |
| Community & Nonprofits | 46 | 1.5% |
| Auto Repair | 44 | 1.5% |
| Medical Offices | 40 | 1.3% |
| Real Estate Agents | 36 | 1.2% |
| Parks & Recreation | 35 | 1.2% |
| Gas Stations | 33 | 1.1% |
| Contractors | 33 | 1.1% |
| Industrial Equipment | 31 | 1.0% |
Adams County Business Listings
| Business | Category | City |
|---|---|---|
| Landmarx Inc. | 3D Printing Service | Quincy |
| Mettemeyer Accounting | Accountant | Quincy |
| Quincy University Health and Fitness Center | Active Life | Quincy |
| Shaw Chiropractic | Acupuncture | Quincy |
| Chelsea Adult Superstore | Adult Entertainment | Quincy |
| Townsquare Media | Advertising Agency | Quincy |
| Quincy Tractor, LLC. | Agricultural Service | Quincy |
| Quincy Regional Airport | Airport | Quincy |
| Julia Montejo, MD | Allergist | Quincy |
| Adams County EMS | Ambulance And Ems Services | Camp Point |
| Download Adams County business listings | ||
Adams County business listings sourced from Overture Maps. Includes locations with a high level of confidence.
Adams County Basemaps
Adams County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.
Get the Full Adams County Data Package
This page shows a preview of what's included in the Adams County data package. The full package gives you a ready-to-use county data system with GIS layers, historical data, maps, database files and planning tools that save hours of manual data gathering, cleanup and joins. Everything is organized to help you skip data wrangling and start analysis faster.
- 20+ GIS layers for zip codes, school districts, roads, water, boundaries and more
- Historical county demographics, housing, income and trend data
- ZIP code population files and school district enrollment history
- Database files, markdowns, AI-ready prompts and documentation
- Map exports in PNG, JPEG, PDF, SVG and GeoTIFF formats
- Offline-ready data explorer, map and analytics tools
Paid packages support commercial use, client work, and derived outputs. Some package contents may include source-specific attribution or provider notices. See Licensing & Data Source Notices.
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Nearby Counties
Browse county data pages for the counties that border Adams County. These nearby pages include the same mix of county maps, demographic summaries, school district context, housing trends and package links.