Carroll County
Illinois · County seat: Mount Carroll · Active county or equivalent
FIPS code 17015 is Carroll County, Illinois. With a population of 15,594 (2022 ACS estimate), it ranks #69 in Illinois and #2112 nationally. The state FIPS code for Illinois is 17. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
17015
Population
15,594
2022 ACS · #2112 nationally
Density
35.1/mi²
people per sq mile
Land Area
445
sq miles
Urban/Rural
Nonmetro — completely rural
RUCC 9
How This FIPS Code Works
The 5-digit FIPS code 17015 is formed by combining the 2-digit state identifier 17 (Illinois) with the 3-digit county identifier 015. Together they uniquely identify Carroll County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 17015
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 17015.
Median Household Income
$61,539
ACS B19013_001E
Poverty Rate
11.2%
ACS B17001 (below poverty level)
Median Age
45.0
ACS B01002_001E
Adjacent Counties (6)
Counties that share a border with Carroll County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 17015.
Federal Datasets Using Code 17015
FIPS code 17015 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 17015 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:015",
"in": "state:17",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Carroll County, Illinois, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '17015';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '17'
AND county_fips = '015';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 17015 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "17",
county = "015",
year = 2022
)ZIP Codes in Carroll County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Carroll County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 61285 | 100.0% |
| 61046 | 100.0% |
| 61074 | 98.1% |
| 61051 | 96.1% |
| 61053 | 90.3% |
| 61014 | 85.0% |
| 61078 | 66.2% |
| 61064 | 4.3% |
| 61062 | 2.3% |
| 61270 | 1.0% |
| 61028 | 0.3% |