Knox County, Illinois

Knox County, Illinois
Location within the U.S. state of Illinois
Coordinates: 40°56′N 90°13′W / 40.93°N 90.21°W / 40.93; -90.21
Country United States
State Illinois
Founded1825
Named afterHenry Knox
SeatGalesburg
Largest cityGalesburg
Government
 • Board ChairmanJared Hawkinson
Area
 • Total
720 sq mi (1,900 km2)
 • Land716 sq mi (1,850 km2)
 • Water3.4 sq mi (8.8 km2)  0.5%
Population
 (2020)
 • Total
49,967
 • Estimate 
(2024)
48,716 [1]
 • Density69.8/sq mi (26.9/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional district17th
Websiteknoxcountyil.gov

Knox County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 49,967.[2] Its county seat is Galesburg.[3] Knox County comprises the Galesburg, IL Micropolitan Statistical Area.

History

Knox County was named in honor of Henry Knox, the first US Secretary of War.[4]

The first "Knox County" in what today is Illinois was unrelated to the modern incarnation. In 1790, the land of the Indiana Territory that was to become Illinois was divided into two counties: St. Clair and Knox. The latter included land in what was to become Indiana. When Knox County, Indiana, was formed from this portion of the county in 1809, the Illinois portions were subdivided into counties that were given other names.

The modern Knox County, Illinois, was organized in 1825, from Fulton County, itself a portion of the original St. Clair County.

Like its neighbor to the south, Fulton County, for its Spoon River Drive, Knox County is also known for a similar scenic drive fall festival the first two weekends in October, the Knox County Drive.

Geography

According to the U.S. Census Bureau, the county has a total area of 720 square miles (1,900 km2), of which 716 square miles (1,850 km2) is land and 3.4 square miles (8.8 km2) (0.5%) is water.[5]

Climate and weather

Galesburg, Illinois
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
1.4
 
 
29
13
 
 
1.6
 
 
35
19
 
 
2.8
 
 
48
29
 
 
3.8
 
 
61
40
 
 
4
 
 
73
51
 
 
4.2
 
 
81
61
 
 
4.4
 
 
85
65
 
 
4.1
 
 
82
63
 
 
3.5
 
 
75
55
 
 
2.5
 
 
63
43
 
 
2.7
 
 
47
31
 
 
2.3
 
 
33
19
Average max. and min. temperatures in °F
Precipitation totals in inches
Source: The Weather Channel[6]
Metric conversion
J
F
M
A
M
J
J
A
S
O
N
D
 
 
36
 
 
−2
−11
 
 
39
 
 
2
−7
 
 
72
 
 
9
−2
 
 
97
 
 
16
4
 
 
101
 
 
23
11
 
 
106
 
 
27
16
 
 
111
 
 
29
18
 
 
103
 
 
28
17
 
 
89
 
 
24
13
 
 
64
 
 
17
6
 
 
69
 
 
8
−1
 
 
58
 
 
1
−7
Average max. and min. temperatures in °C
Precipitation totals in mm

In recent years, average temperatures in the county seat of Galesburg have ranged from a low of 13 °F (−11 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −25 °F (−32 °C) was recorded in January 1982 and a record high of 102 °F (39 °C) was recorded in July 1983. Average monthly precipitation ranged from 1.41 inches (36 mm) in January to 4.37 inches (111 mm) in July.[6]

Public Transit

Major highways

Adjacent counties

Demographics

Historical population
CensusPop.Note
1830274
18407,0602,476.6%
185013,27988.1%
186028,663115.9%
187039,52237.9%
188038,344−3.0%
189038,7521.1%
190043,61212.5%
191046,1595.8%
192046,7271.2%
193051,3369.9%
194052,2501.8%
195054,3664.0%
196061,28012.7%
197061,2800.0%
198061,6070.5%
199056,393−8.5%
200055,836−1.0%
201052,919−5.2%
202049,967−5.6%
2024 (est.)48,716[7] −2.5%
U.S. Decennial Census[8]
1790-1960[9] 1900-1990[10]
1990-2000[11] 2010-2013[2]

2020 census

As of the 2020 census, the county had a population of 49,967. The median age was 43.3 years. 19.9% of residents were under the age of 18 and 22.2% of residents were 65 years of age or older. For every 100 females there were 101.7 males, and for every 100 females age 18 and over there were 100.6 males age 18 and over.[12]

The racial makeup of the county was 81.4% White, 8.9% Black or African American, 0.2% American Indian and Alaska Native, 0.7% Asian, <0.1% Native Hawaiian and Pacific Islander, 2.3% from some other race, and 6.4% from two or more races. Hispanic or Latino residents of any race comprised 6.1% of the population.[13]

67.7% of residents lived in urban areas, while 32.3% lived in rural areas.[14]

There were 20,851 households in the county, of which 25.4% had children under the age of 18 living in them. Of all households, 41.1% were married-couple households, 20.8% were households with a male householder and no spouse or partner present, and 30.2% were households with a female householder and no spouse or partner present. About 35.1% of all households were made up of individuals and 17.1% had someone living alone who was 65 years of age or older.[12]

There were 23,817 housing units, of which 12.5% were vacant. Among occupied housing units, 68.5% were owner-occupied and 31.5% were renter-occupied. The homeowner vacancy rate was 2.9% and the rental vacancy rate was 9.1%.[12]

Racial and ethnic composition

Knox County, Illinois – Racial and ethnic composition
Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.
Race / Ethnicity (NH = Non-Hispanic) Pop 1980[15] Pop 1990[16] Pop 2000[17] Pop 2010[18] Pop 2020[19] % 1980 % 1990 % 2000 % 2010 % 2020
White alone (NH) 58,025 51,744 49,355 45,132 39,615 94.19% 91.76% 88.39% 85.29% 79.28%
Black or African American alone (NH) 1,987 2,804 3,472 3,741 4,354 3.23% 4.97% 6.22% 7.07% 8.71%
Native American or Alaska Native alone (NH) 66 82 83 75 73 0.11% 0.15% 0.15% 0.14% 0.15%
Asian alone (NH) 201 319 382 331 361 0.33% 0.57% 0.68% 0.63% 0.72%
Native Hawaiian or Pacific Islander alone (NH) x [20] x [21] 8 7 12 x x 0.01% 0.01% 0.02%
Other race alone (NH) 86 28 36 44 207 0.14% 0.05% 0.06% 0.08% 0.41%
Mixed race or Multiracial (NH) x [22] x [23] 604 1,031 2,294 x x 1.08% 1.95% 4.59%
Hispanic or Latino (any race) 1,242 1,416 1,896 2,558 3,051 2.02% 2.51% 3.40% 4.83% 6.11%
Total 61,607 56,393 55,836 52,919 49,967 100.00% 100.00% 100.00% 100.00% 100.00%

2010 census

As of the 2010 United States census, there were 52,919 people, 21,535 households, and 13,324 families residing in the county.[24] The population density was 73.9 inhabitants per square mile (28.5/km2). There were 24,077 housing units at an average density of 33.6 per square mile (13.0/km2).[5] The racial makeup of the county was 87.5% white, 7.2% black or African American, 0.6% Asian, 0.2% American Indian, 1.9% from other races, and 2.5% from two or more races. Those of Hispanic or Latino origin made up 4.8% of the population.[24] In terms of ancestry, 23.1% were German, 14.9% were Irish, 11.7% were English, 11.6% were Swedish, and 8.0% were American.[25]

Of the 21,535 households, 27.2% had children under the age of 18 living with them, 45.7% were married couples living together, 11.9% had a female householder with no husband present, 38.1% were non-families, and 32.3% of all households were made up of individuals. The average household size was 2.27 and the average family size was 2.84. The median age was 42.0 years.[24]

The median income for a household in the county was $39,545 and the median income for a family was $51,740. Males had a median income of $42,067 versus $25,380 for females. The per capita income for the county was $20,908. About 10.9% of families and 15.5% of the population were below the poverty line, including 24.7% of those under age 18 and 7.3% of those age 65 or over.[26]

Communities

Cities

Villages

Census-designated places

Other unincorporated communities

Townships

Knox County is divided into twenty-one townships:

Politics

Knox County's political history is typical of Yankee-settled Northern Illinois. It leaned Whig during its early elections – although giving a plurality to Franklin Pierce in 1852 – and become powerfully Republican following that party's formation. Although Knox did support Progressive Theodore Roosevelt against conservative incumbent President William Howard Taft in 1912, it was Franklin D. Roosevelt’s 1932 landslide before Knox County again gave the Democratic Party so much as a plurality, and it did not give a Democratic absolute majority until Lyndon B. Johnson gained such against the anti-Yankee, Southern-leaning Barry Goldwater in 1964.

Since then, Knox County gradually trended Democratic for the following four decades, so that Michael Dukakis in his losing 1988 campaign was able to carry the county by the same margin as Johnson had done in 1964. During the 1990s and 2000s, Knox was a solidly Democratic county, voting Democratic by at least nine percentage points in every election from 1992 to 2012. The 2016 election, in the shadow of high unemployment in the “Rust Belt” saw a swing of over twenty percentage points to Donald Trump, who became the first Republican victor in the county since Ronald Reagan in 1984.

United States presidential election results for Knox County, Illinois[27]
Year Republican Democratic Third party(ies)
No.  % No.  % No.  %
1892 5,800 60.49% 3,073 32.05% 715 7.46%
1896 7,681 67.39% 3,480 30.53% 236 2.07%
1900 7,810 67.62% 3,299 28.57% 440 3.81%
1904 7,566 73.84% 1,849 18.04% 832 8.12%
1908 7,084 63.83% 3,277 29.53% 737 6.64%
1912 1,750 16.72% 2,758 26.35% 5,959 56.93%
1916 10,918 58.82% 6,785 36.55% 860 4.63%
1920 12,559 73.85% 2,852 16.77% 1,594 9.37%
1924 12,968 65.89% 2,617 13.30% 4,095 20.81%
1928 16,151 72.33% 5,993 26.84% 186 0.83%
1932 12,244 49.14% 12,282 49.29% 392 1.57%
1936 14,712 50.52% 13,697 47.03% 715 2.46%
1940 17,459 57.77% 12,597 41.68% 168 0.56%
1944 15,964 61.02% 10,070 38.49% 126 0.48%
1948 15,016 60.18% 9,772 39.16% 164 0.66%
1952 18,569 64.16% 10,354 35.78% 17 0.06%
1956 18,656 66.04% 9,558 33.83% 37 0.13%
1960 17,938 60.09% 11,889 39.83% 23 0.08%
1964 12,850 46.14% 15,000 53.86% 0 0.00%
1968 14,216 53.86% 9,707 36.77% 2,473 9.37%
1972 17,315 64.69% 9,333 34.87% 118 0.44%
1976 14,123 54.39% 11,525 44.38% 319 1.23%
1980 14,907 56.90% 8,749 33.40% 2,542 9.70%
1984 14,974 55.21% 12,027 44.34% 121 0.45%
1988 10,842 45.75% 12,752 53.81% 106 0.45%
1992 8,331 32.93% 12,524 49.51% 4,441 17.56%
1996 7,822 34.69% 12,487 55.38% 2,239 9.93%
2000 9,912 42.77% 12,572 54.25% 690 2.98%
2004 11,111 44.97% 13,403 54.25% 194 0.79%
2008 9,419 39.09% 14,191 58.89% 488 2.03%
2012 9,408 40.28% 13,451 57.59% 497 2.13%
2016 10,737 47.71% 10,083 44.81% 1,683 7.48%
2020 12,009 51.75% 10,703 46.12% 496 2.14%
2024 11,917 53.45% 9,838 44.13% 540 2.42%

See also

References

  1. ^ "County Population Totals and Components of Change: 2020–2024". United States Census Bureau. U.S. Department of Commerce. March 2025. Retrieved August 31, 2025.
  2. ^ a b "State & County QuickFacts". United States Census Bureau. Archived from the original on June 6, 2011. Retrieved July 6, 2014.
  3. ^ "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
  4. ^ Gannett, Henry (1905). The Origin of Certain Place Names in the United States. Government Printing Office. pp. 177.
  5. ^ a b "Population, Housing Units, Area, and Density: 2010 - County". United States Census Bureau. Retrieved July 12, 2015.{{cite web}}: CS1 maint: deprecated archival service (link)
  6. ^ a b "Monthly Averages for Galesburg, Illinois". The Weather Channel. Retrieved January 27, 2011.
  7. ^ "Population and Housing Unit Estimates Tables". United States Census Bureau. Retrieved July 24, 2025.
  8. ^ "U.S. Decennial Census". United States Census Bureau. Retrieved July 6, 2014.
  9. ^ "Historical Census Browser". University of Virginia Library. Retrieved July 6, 2014.
  10. ^ "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Retrieved July 6, 2014.
  11. ^ "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. Archived (PDF) from the original on March 27, 2010. Retrieved July 6, 2014.
  12. ^ a b c "2020 Decennial Census Demographic Profile (DP1)". United States Census Bureau. 2021. Retrieved December 25, 2025.
  13. ^ "2020 Decennial Census Redistricting Data (Public Law 94-171)". United States Census Bureau. 2021. Retrieved December 25, 2025.
  14. ^ "2020 Decennial Census Demographic and Housing Characteristics (DHC)". United States Census Bureau. 2023. Retrieved December 25, 2025.
  15. ^ "1980 Census of Population - General Population Characteristics - Illinois- Table 14 - Persons by Race and Table 16 (p. 18-28) - Total Persons and Spanish Origin Persons by Type of Spanish Origin and Race (p. 29-39)" (PDF). United States Census Bureau.
  16. ^ "1990 Census of Population - General Population Characteristics - Illinois - Table 6 - Race and Hispanic Orogin" (PDF). United States Census Bureau.
  17. ^ "P004: Hispanic or Latino, and Not Hispanic or Latino by Race – 2000: DEC Summary File 1 – Knox County, Illinois". United States Census Bureau.
  18. ^ "P2: Hispanic or Latino, and Not Hispanic or Latino by Race – 2010: DEC Redistricting Data (PL 94-171) – Knox County, Illinois". United States Census Bureau.
  19. ^ "P2: Hispanic or Latino, and Not Hispanic or Latino by Race – 2020: DEC Redistricting Data (PL 94-171) – Knox County, Illinois". United States Census Bureau.
  20. ^ included in the Asian category in the 1980 Census
  21. ^ included in the Asian category in the 1990 Census
  22. ^ not an option in the 1980 Census
  23. ^ not an option in the 1990 Census
  24. ^ a b c "DP-1 Profile of General Population and Housing Characteristics: 2010 Demographic Profile Data". United States Census Bureau. Retrieved July 12, 2015.{{cite web}}: CS1 maint: deprecated archival service (link)
  25. ^ "DP02 SELECTED SOCIAL CHARACTERISTICS IN THE UNITED STATES – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Retrieved July 12, 2015.{{cite web}}: CS1 maint: deprecated archival service (link)
  26. ^ "DP03 SELECTED ECONOMIC CHARACTERISTICS – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Retrieved July 12, 2015.{{cite web}}: CS1 maint: deprecated archival service (link)
  27. ^ Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Retrieved March 19, 2018.

Further reading

40°56′N 90°13′W / 40.93°N 90.21°W / 40.93; -90.21